Characterization of microsatellites in Fusicladium effusum, cause of pecan scab.

Pecan scab, caused by the plant pathogenic fungus Fusicladium effusum, is the most destructive disease of pecan. Little is known of the population genetic diversity of this pathogen. In this study, microsatellites were mined from the F. effusum genome, and flanking primers were subsequently designed. A total of 275 microsatellites were screened, and 33 selected primers produced reliable, polymorphic markers against 46 isolates of F. effusum from 11 diverse locations in the southeastern USA. The number of alleles per microsatellite locus ranged from two to 17, and the polymorphic information content ( PIC) from 0.475 to 0.911. A unique pattern informative combination ( UPIC) analysis of three groups of 12 isolates each and 33 primers consistently showed a minimum number of markers required for the maximum discrimination of isolates equal to 3. The characteristics of the unique patterns ( UP) and informative contents ( IC) were very similar. However, the primers that were selected by UPIC were not necessarily the same for each of the three groups. Using all 46 isolates showed each locus was polymorphic, with a single-population level Shannon's information index of 1.516, indicating substantial diversity. These markers show a range in polymorphic content and power of discrimination that will be valuable tools for studies of genetic diversity in F. effusum. [ABSTRACT FROM AUTHOR]