The present study showed a genetic differentiation (Gst)
of 0.09, implying that 9% of the total genetic variation was
among the populations, with the remaining 91% of variation
residing within the populations. Yeh (2000) considered a Gst
range between 0.151 and 0.25 as representative of large
genetic differentiation. Based on this range, the soybean populations
of the Korean landraces showed little differentiation
among the populations in the eight Korean locations.
Additionally, this study estimated the amount of gene flow
(Nm = 4.7971) to be moderate. Hamrick and Nason (2000)
suggested four migrants per generation (Nm = 3.54) as the
minimum number to prevent differentiation due to drift.
According to Wright (1969), the critical value for Nm is 0.5.
An Nm value below 1 indicates that the populations began to
differentiate due to genetic drift. Furthermore, it has been
proposed that an Nm value below 0.5 indicates that populations
will diverge extensively as a result of drift (Mcdermott
and Mcdonald 1993). Overall, the calculated gene flow (Nm)
indicated that the Korean soybean landraces are in the
process of differentiation.