Conditions and procedures of PCR amplifications using dominant
markers were performed as described by Jia et al. (2002, 2004a). The
PCR products (10 l l) were separated by electrophoresis on 1.5% (w/v)
agarose gels in 1X TBE buffer, stained in ethidium bromide and
visualized using an ultraviolet transilluminator. All PCR reactions for
each sample were repeated at least once to confirm results