Genetic diversity
The total length of aligned sequences for the three chloroplast
fragments (matK , trnD-E , trnS-G ) was 2161 bp with
25 variable sites, including 21 single nucleotide variant sites, 2 6-bp
insertions and 5 deletions in 323 individuals, and 661 bp for ITS with
10 variable sites in 174 individuals from 18 Cerasus serrulatapopulations. Results of diversity analyses were shown in Table 1. At
species level, the haplotype diversity (H d) was
0.828 and the ribotype diversity (R d) was 0.673;
the nucleotide diversity (P i) of cpDNA and ITS
were 1.490 and 2.521, respectively. All of the data suggested a high
genetic diversity of Cerasus serrulata . At population level,H d varied from 0.000 to 0.700 whileR d varied from 0.000 to 0.733;P i×10-3 of cpDNA varied from
0.000 to 1.090 while that of ITS varied from 0.000 to 2.820. Population
CPL showed the highest haplotype diversity both in cpDNA and ITS
regions. Combing the geographic distribution (Figure 1) along with
haplotype distribution (Figure 1, 4), networks (Figure 2, 5) and
cladograms (Figure 3, 6), four regions of groups were divided (Table 1).
At region level, H d varied from 0.266 to 0.747
and R d varied from 0.246 to 0.752, whileP i varied from 0.280 to 1.940 for cpDNA, and from
0.370 to 1.670 for ITS. Both kinds of sequences revealed a lowest
diversity level in Northwest China (NW). But differently, region in
Southeast China (SE) showed a highest H d while
region in Southwest China (SW) showed a highest Rd, indicating a highest
haplotype/ribotype diversity level in South China.