Microsatellite sequences in Pinus sylvestris

Scots pine (Pinus sylvestris) genomic libraries were constructed and screened with oligonucleotide probes (GT)(10),(CT)(10), and (AT)(10). Eight microsatellites were identified from 6000 clones screened. The longest microsatellite stretch found (GT)(9)(N)(21)(AT)(24), was amplified from bud and single pollen grain samples. In order to clarify the complex amplification pattern revealed, two PCR products were sequenced. The size differences were caused both by varying repeat numbers of the microsatellite stretches and by differences in other parts of the amplified sequence. This kind of complex molecular basis of microsatellite amplification within a species has not been previously reported. Microsatellite sequences were used as PCR primers to detect polymorphisms and to estimate the abundance of microsatellites.