Evaluation of microsatellite markers for characterizing chestnut cultivars

Microsatellites or simple sequence repeats (SSR) are increasingly becoming the tool of choice for genetic studies due to their high polymorphism and the ease with which the polymorphism can be detected. Recent studies have shown that SSRs are conserved in related species and this fact may allow the analysis of different species using the same microsatellite loci. In this research SSR markers isolated in Quercus robur and Quercus petraea were tested on four cultivars of Castanea sativa Mill., including a 'marrone' type variety, and on the hybrid Marigoule (C. crenata X C. sativa) to evaluate their informativeness for genotyping of chestnut. Thirty loci were screened and 12 primer pairs were able to amplify DNA fragments in chestnut of about the same size as in oaks. Preliminary analysis on sequencing gels revealed positive hybridization signals using a (GA)(13) oligonucleotide as a probe. This indicates the presence of the microsatellite in the amplified PCR products. At nine loci two or more PCR products of the expected size were detected and hence considered to be polymorphic. The results demonstrate the possibility of using SSR markers isolated in Quercus for the genotyping of Castanea.