Staff Profiles

Peter H. Thrall

Research Scientist
Ph.D., Duke University, USA, 1993

Phone (+61) 02 6246 5126
Fax: (+61) 02 6246 5249

E-mail: Peter.Thrall@csiro.au

Centre for Plant Biodiversity Research
CSIRO Plant Industry
GPO Box 1600
Canberra ACT 2601
AUSTRALIA

My research addresses the ecological and evolutionary dynamics of host-microbe interactions in natural systems. Current projects include basic research on coevolution in natural plant-pathogen associations, and the use of microbial symbionts in restoration and rehabilitation of natural plant communities.

Broad understanding of the ecological and evolutionary dynamics of disease depends fundamentally on recognising that such interactions occur in heterogeneous environments that can vary dramatically in space and time. My research combines long-term studies of wild host-pathogen systems with modeling to investigate how the interplay of demographic and genetic processes influences the coevolution of host resistance and pathogen infectivity at spatial scales ranging from single populations to metapopulations and beyond. Current empirical projects focus on (i) understanding how the genetic diversity of host resistance and pathogen infectivity interact to influence the severity of disease epidemics and the coevolutionary process; and (ii) the impact of host resistance diversity on the evolutionary balance between pathogen infectivity and virulence. The modeling work emphasises general issues related to the maintenance of genetic polymorphisms in host resistance and pathogen infectivity in relation to host and pathogen life-histories (e.g. mating system, transmission mode), and the spatial scales at which they disperse.

In the low nutrient soils typical of Australia, interactions between native legumes and their bacterial symbionts result in nitrogen-fixing partnerships that are important in conservation management, the sustainable use of agricultural lands and the restoration of degraded ecosystems. Despite this, little is known about the diversity of native Australian rhizobia or their host specificity. Research in this area focuses on investigating: (i) how interactions between rhizobia and hosts influence dynamics of shrubby plant communities; ii) examining the link between rhizobial effectiveness and phylogenetic relatedness of hosts; iii) assessing the range of variation in the ability of rhizobia to promote growth and survivorship of different host species; and iv) applying information on rhizobial effectiveness to improve the success of revegetation programs, and to determine under what conditions it is necessary to inoculate soils. This work is particularly critical for developing guidelines for effective re-introduction of native vegetation, as well as understanding ecological interactions that influence plant community diversity.

• Antonovics J, Thrall PH. 1994. The cost of resistance and the maintenance of genetic polymorphism in host-pathogen systems. Proc Roy Soc Lond B 257:105-110.
  

• Thrall PH, Biere A, Uyenoyama MK. 1995. Frequency dependent disease transmission and the dynamics of the Silene-Ustilago host/pathogen system. Am Nat 145:43-62.
  

• Thrall PH, Antonovics J. 1995. Theoretical and empirical studies of metapopulations: population and genetic dynamics of the Silene-Ustilago system. Can J Bot 73:S1249-S1258.
  

• Lockhart A, Thrall PH, Antonovics J. 1996. Sexually-transmitted diseases in animals: ecological and evolutionary implications. Biol Rev Camb Phil Soc 71:415-471.
  

• Thrall PH, Antonovics J, Bever JD. 1997. Sexual transmission of disease and host mating systems: within season reproductive success. Am Nat 149:485-506.
  

• Thrall PH, Antonovics J. 1997. Polymorphism in sexual vs. non-sexual disease transmission. Proc Roy Soc Lond B 264:581-587.
  

• Thrall PH, Burdon JJ. 1997. Host pathogen dynamics in a metapopulation context: the ecological and evolutionary consequences of being spatial. J Ecol 85:743-753.
  

• Thrall PH, Antonovics J, Wilson WG. 1998. Allocation to sexual vs. non-sexual disease transmission. Am Nat 151:29-45.
  

• Thrall PH, Burdon JJ. 1999. The spatial scale of pathogen dispersal: consequences for disease dynamics and persistence. Evolutionary Ecology Research 1:681-701.
  

• Burdon JJ, Thrall PH. 1999. Spatial and temporal patterns in coevolving plant and pathogen associations. Am Nat 153:S15-S33.
  

• Burdon JJ, Thrall PH, Brown AHD. 1999. Resistance and virulence structure in two Linum marginale - Melampsora lini host-pathogen metapopulations with different mating systems. Evolution 53:704-716.
  

• Thrall PH, Burdon JJ, Woods M. 2000. Variation in the effectiveness of symbiotic associations between native rhizobia and temperate Australian legumes: within and among genera interactions. J Appl Ecol 37:52-65.
  

• Thrall PH, Antonovics J, Dobson AP. 2000. Dynamics and prevalence of sexually transmitted diseases in polygynous mating systems. Proc Roy Soc Lond B 267:1-9.
  

• Burdon JJ, Thrall PH. 2000. Coevolution at multiple spatial scales - from population to continent and beyond. Evolutionary Ecology 14:261-281.
  

• Thrall PH, Burdon JJ. 2000. Effect of resistance variation in a natural plant host-pathogen metapopulation on disease dynamics. Plant Pathology 49:767-773.
  

• Thrall PH, Burdon JJ, Young A. 2001. Variation in resistance and virulence among demes of a single host-pathogen metapopulation. J Ecol 89:736-748.
  

• Thrall PH, Burdon JJ, Bock C. 2001. Short-term epidemic dynamics in the Cakile maritima-Alternaria brassicicola host-pathogen metapopulation association. J Ecol 89:723-735.
  

• Thrall PH, Burdon JJ. 2002. The evolution of gene-for-gene interactions: consequences of variation in host and pathogen dispersal. Plant Pathol 51:169-184.
  

• Thrall PH, Burdon JJ, Bever JD. 2002. Local adaptation in the Linum marginale-Melampsora lini host-pathogen interaction. Evolution.

Evolution of Plant-Pathogen Associations
Plant-Microbial Associations & Restoration Ecology
Biocontrol of Weeds
Ecological Genetics of Endangered Plants
Modelling Effects of Self-incompatibility on Plant Population Viability
Ecosysytem Restoration