Analyzing Pathogen Populations Using Molecular Markers.

DNA probes are useful markers for studying pathogen population genetics. Repetitive probes may produce characteristic "fingerprints" that identify strains or lineages of asexually-reproducing pathogens. Relatedness among strains can be inferred, giving insight into the processes of race evolution, gene flow, and other aspects of pathogen population biology. Information about pathogen population dynamics may be useful in designing improved strategies for disease management. Knowledge of pathogen lineages can also be used in the selection of diverse tester strains used in screening of breeding material for crop improvement. Different probes may reveal somewhat different information about a population. The specific estimates of diversity obtained for a given population depend on the specific probe employed in the analysis. Probes may vary in the extent to which they reveal RFLP patterns that are associated with pathogenic race. If there is a perfect association between RFLP type and race, a probe may be used to identify race. The extent of association between identified molecular and pathogenic phenotypes depends upon the characteristics of the population tested, of the differential cultivars chosen for virulence analysis, and of the probe and enzyme used for the analysis of RFLP type. [ABSTRACT FROM AUTHOR]