Triplet-repeat microsatellites shared among hard and soft pines

Vascular plant species have shown a low level of microsatellite conservatio n compared to many animal species. Finding trans-specific microsatellites f or plants may be improved by using a prior! knowledge of genome organizatio n. Fifteen triplet-repeat microsatellites from hard pine (Pinus taeda L.) w ere tested for trans-specific amplification across seven hard pines (P. pal ustris Mill., P. echinata Mill., P. radiata D. Don., P. patula Schiede et D eppe, P. halepensis Mill., P. kesiya Royle), a soft pine (P. strobus L.), a nd Picea rubens Sargent. Seven of 15 microsatellites had trans-specific amp lification in both hard and soft pine subgenera. Two P. taeda microsatellit es had conserved flanking regions and repeat motifs in all seven hard pines , soft pine P. strobus, and P. rubens. Perfect triplet-repeat P. taeda micr osatellites appear to be better candidates for trans-specific polymorphism than compound microsatellites. Not all perfect triplet-repeat microsatellit es were conserved, but all conserved microsatellites had perfect repeat mot ifs. Persistent microsatellites PtTX2123 and PtTX3020 had highly conserved flanking regions and a conserved repeat motif composition with variable rep eat unit numbers. Using trinucleotide microsatellites improved trans-specif ic microsatellite recovery among hard and soft pine species.