**5.2 Genetic distance**

The Kimura two-parameter (K2P) distance varied from 0.0014 to 0.0132, with the distance between Pu'er (southern Yunnan) and Yongsheng (northern Yunnan) being the minimum and that between Stone Forest (central Yunnan) and Hubei being the maximum (Table 2). The K2P distances among populations from Pu'er, Huaning, Stone Forest, and Yongsheng and among populations from Ruili, Wanding, and Lianghe showed close genetic connection; but the K2P distances between any given population from Pu'er, Huanian, Stone Forest, or Yongsheng and that from Ruili, Wanding, or Lianghe suggested otherwise (Table 2). Hence,

Detecting Non-Local Japanese Pine Sawyers

from the remaining ones involved in the research.

**5.4 Population genetic structure** 

**5.3 Phylogenetic cladistics** 

in Yunnan, Southwestern China via Modern Molecular Techniques 77

The neighbor-joining (NJ) phylogenetic tree based on the K2P distance of the 18 haplotypes resolved three major clades designated from A to C (Fig. 5). Clade A contained six populations from Yunnan, with four from northern, central, and southern portion, and only one sample from Wanding, southwestern portion was included. Clade B contained the three populations from southwestern Yunnan and the population from Zhejiang, eastern China. However, no sample from other portions of Yunnan grouped in clade B. Clade C only contained the population from Hubei, central China. The topological structure of the NJ phylogenetic tree suggests that the seven populations consisted of two groups, the RPG and the SPG, regardless of the connection between them by a few samples from Wanding and Lianghe. It also suggested that the genetic profile of the population from Hubei is different

Fig. 5. The neighbor-joining (NJ) phylogenetic tree of the 18 haplotypes of *M. alternatus*, numbers above the branches represent the bootstrap values (> 50). After Fu et al. (2010).

SAMOVA and AMOVA analyses were applied to verify the genetic structure of the seven populations from Yunnan. When the number of groups (*K*) grows and the *F*CT value reaches the plateau, the SAMOVA analysis yields the optimal result. In this research, the *F*CT value reached the maximum (*F*CT = 0.73) when *K* = 2, with populations from Pu'er, Huaning, Stone Forest, and Yongsheng being one group and populations from Ruili, Wanding, and Lianghe being the other (Fig. 6), supporting the grouping result mentioned previously. The grouping was then tested by the AMOVA analysis, which indicated that 72.54% of the variation

the seven populations sampled from Yunnan could be divided into two groups, hereafter designated as the SPG, the southwestern population group containing populations from Ruili, Wanding, and Lianghe, and the RPG, the remaining population group containing populations from Pu'er, Huaning, Stone Forest, and Yongsheng. The grouping result was then supported by the multidimensional scaling (MDS) analysis (Fig. 4). Notably, both the K2P distances and the MDS analysis showed a close relationship between the population from Zhejiang and all populations from the SPG, however, the relationship between the population from Hubei and any population from both the SPG and the RPG was much greater (Table 2; Fig. 4).


Table 2. Matrix of the Kimura two-parameter (K2P) distance (below diagonal) and standard errors (above diagonal) of between populations of *M. alternatus*. Population codes correspond to those in Fig. 2. Data source: Fu et al. (2010).

Fig. 4. The multidimensional scaling (MDS) plots of *M. alternatus* populations at different locations based on Kimura two-parameter (K2P) distances. SPG, the southwestern population group; RPG, the remaining population group. Population codes correspond to those in Fig. 2. After Fu et al. (2010).
