An enrichment cloning method was evaluated for the isolation of micros
atellite loci from eastern white pine and the resulting markers were e
xamined for polymorphisms. A 200-fold enrichment was achieved for high
ly abundant (AC)(n) repeats, but for much less abundant (ACAG)(n) repe
ats an enrichment of only 20-fold was obtained. Using a single set of
PCR conditions, 19 microsatellite loci were identified from 77 primer
pairs evaluated. Genotyping of 16 (AC)(n) loci in 16 unrelated white p
ines from the north-central United States revealed an average of 5.4 a
lleles per locus and an average observed heterozygosity of 0.515. Five
loci were scored among megagametophytes from a single pine to obtain
a haploid genotype of the segregating female meiotic products. All loc
i segregated according to Mendelian expectations and linkage was estab
lished for two of the loci. It was concluded that (AC)(n) loci are hig
hly variable in this species and that SSR (simple sequence repeat) mar
kers can be efficiently developed for genome mapping and population ge
netics studies.