Microsatellite polymorphism in Dioscorea tokoro, a wild yam species.

Six microsatellite loci were characterized in Dioscorea tokoro, a wild yam species in East Asia. All six loci were polymorphic in a sample of 23 individuals from natural populations in Japan. The microsatellite loci displayed many alleles (6.2 alleles per locus on average), and the observed heterozygosity (Ho = 0.54) as well as expected heterozygosity (He = 0.68) were high. The heterozygosities were far more than that previously detected by allozyme analysis of D. tokoro (Ho = 0.23, He = 0.28). Five microsatellite loci were sufficient to provide a paternity exclusion rate (Q) of Q = 0.98, which enables monitoring of the pollen-mediated gene flow between plants in a population. Microsatellite loci are abundant and highly polymorphic in D. tokoro and other plants and are therefore ideal markers for plant population genetic studies.