Microsatellite markers derived from Quercus mongolica var. crispula (Fagaceae) inner bark expressed sequence tags

Abstract

In reforestation programs the genetic composition and diversity of populations that could be used as sources of planting material needs to be carefully considered to maximize the chances of successful establishment. For such purposes genetic analyses that include the identification of functional genes are required. In this study, we constructed a cDNA library from inner bark of Quercus mongolica (which is widely distributed in Japan) and collected 3385 ESTs. After constructing 2140 unigenes, 274 microsatellites were found within them. The most frequent microsatellite had AG motif (48%) and the next most common was AAG motif (12%). There were no CG repeats in the unigenes. In total, 20 EST-SSR markers were developed, polymorphisms of which were described by using eight individuals from eight populations over the species' distributional range. The number of alleles per locus (Na) and observed heterozygosity (H(o)) ranged from 2 to 12, and from 0.25 to 1.00, respectively. Cross-species amplification was successful for 19 loci in eight individuals of Q. serrata and for 20 loci in eight individuals of Q. dentata, with values of Na and H(o) comparable to those of Q. mongolica. The EST-SSR markers characterized in this study should facilitate the analysis of genetic diversity in future studies.