2.4. Data analysis
Each band in PCR products was considered as a separate putative locus which was scored as present (1) or absent (0). Only intensely stained, unambiguous, clear bands, with size between 140 bp and 622 bp, were used for statistical analysis. Phylogenetic inference was performed with NTSYS-pc (version 2.1) (Rohlf, 2000). Pair-wise comparisons were calculated using the Dice coefficient. The unweighted paired group method using arithmetic averages (UPGMA) was used to construct the phylogenetic tree of these cultivars. Kappa index and Dice coefficient evaluated cultivar consistency of the cultivars considered identical, Longzi and Lao Longzi, were calculated using SAS 8.0 (Cary, United States) and SPSS 11.5 (Chicago, United States). In addition, cross tabulation and PCoA analysis in NTSYS-pc (version 2.1) (Rohlf, 2000) were used to study the EST-SSR fingerprint difference among different horticultural types.