Genetic structure
Analysis of molecular variance (AMOVA) revealed a high differentiation level of both cpDNA (F st=0.69325) and ITS (F st=0.78692) in C. serrulata (Table 2). It was estimated that 69.32% of the whole variations of cpDNA sequences and 78.69% of the whole variations of ITS sequences existed among populations, signifying a phylogeographic structure in C. serrulata (N ST=0.388 >G ST=0.328, P < 0.05) (Table 3). But in detail, groups in northwest (NW) (N ST=0.305 <G ST=0.461, P > 0.05) and northeast (NE) (N ST=0.496 >G ST=0.473, P < 0.05) showed no or weak phylogeographic structure.