New microsatellite loci for water yam (Dioscorea alata, Dioscoreaceae) and cross-amplification for other Dioscorea species.

PREMISE OF THE STUDY Dioscorea alata L. is one of the most widely distributed species of the genus in the humid and semihumid tropics and is associated with traditional agriculture. Only a few microsatellite markers have been developed so far for this and other Dioscorea species. METHODS AND RESULTS We isolated 14 codominant polymorphic microsatellite markers using a microsatellite-enriched genomic library technique. Ten microsatellite loci were selected, and 80 D. alata accessions from different regions in Brazil were evaluated with nine polymorphic loci. The polymorphism information content (PIC) varied from 0.39 to 0.78 and the power discrimination (PD) ranged from 0.15 to 0.91. Six of the markers showed transferability for the species D. bulbifera, D. cayenensis-D. rotundata, and D. trifida. CONCLUSIONS The SSR markers obtained are an important tool for further studies aiming to characterize the genetic diversity in D. alata and other Dioscorea spp. accessions.