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ARS Home » Southeast Area » Byron, Georgia » Fruit and Tree Nut Research » Research » Publications at this Location » Publication #327557

Research Project: Mitigating Alternate Bearing of Pecan

Location: Fruit and Tree Nut Research

Title: Characterization of microsatellites in Fusicladium effusum, cause of pecan scab

Author
item Bock, Clive
item Chen, Chunxian
item Yu, Fahong - University Of Florida
item Stevenson, Katherine - University Of Florida
item Arias De Ares, Renee
item Wood, Bruce

Submitted to: Forest Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/19/2016
Publication Date: 5/10/2016
Citation: Bock, C.H., Chen, C., Yu, F., Stevenson, K.L., Arias De Ares, R.S., Wood, B.W. 2016. Characterization of microsatellites in Fusicladium effusum, cause of pecan scab. Forest Pathology. doi: 10.1111/efp.12278.

Interpretive Summary: Pecan scab (Fusicladium effusum) is a destructive disease of pecan in the US and elsewhere. Little is known of the population genetic diversity of this pathogen. In this study, molecular markers (microsatellites) were developed from the F. effusum genome. Of 275 microsatellites screened, 33 were selected that produced reliable, polymorphic markers against 46 isolates of F. effusum from 11 diverse locations in the Southeastern USA. Screening all 46 isolates with the 33 primers showed each locus was polymorphic with substantial diversity among isolates. These markers show have good power of discrimination that will be valuable tools for studies of genetic diversity and population structure in F. effusum, which can help understand the threat to host resistance.

Technical Abstract: 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 2 to 17; the polymorphic information content (PIC) from 0.475 to 0.911. A unique pattern informative combination (UPIC) analysis of 3 groups of 12 isolates each and 33 primers consistently showed a minimum number of markers required for 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 3 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.