Only unambiguous and reproducible bands were used for data analysis. The percentage of reproducibility was determined
from the number of reproducible bands and the total number of bands observed. The amplified DNA fragments were scored
by presence (1) or absence (0) for each sample. The fragments that were the same in the samples of a population were
referred to as common bands, while those that differed among the samples were referred as polymorphic (Qian and Ge,
2001). It is noteworthy that the seed bank and above ground plants at the same locality were regarded as different populations, and hence there were in total eight populations from the four regions.
The following parameters were calculated using the program POPGENE 1.31 (Yeh et al., 1999) to describe intra- and interpopulation genetic variation as: (1) the mean number of alleles per locus (Ao); (2) the effective number of alleles per locus
(Ae); (3) Nei's gene diversity (H) (Nei, 1973); (4) Shannon information index (I) (King and Schaal, 1989); and (5) the percentage
of polymorphic loci (PPL). Genetic divergence among populations was measured by Nei's unbiased genetic distances and
genetic identities.