Distribution pattern and phylogenetic relationship of ITS ribotypes
A total of 9 ITS ribotypes were identified in the 174 individuals (Figure 4, Table 1). Of all the ribotypes, 5 were unique only to one population and ribotype R4 was the most standard ribotype which covered 12 populations, and was the unique ribotype for 7 populations.
Taken together, the distribution pattern (Figure 4), ribotype network (Figure 5) and phylogenetic tree (Figure 6) exhibited a structure with 2 groups of these ribotypes which was consistent with the cpDNA haplotype relationship in a lower resolution. Group one, consisting of 5 ribotypes (R1-R5) with R4 being the most extraordinary ribotype, and involving 13 populations as the utmost group, located in Southeast China and the southwest region (SW+SE). Group two incorporated 4 ribotypes (R6-R9) , taking R7 as the main ribotype, distributed discontinuously in the northwest region and around Korea (including population FHS in China), covering the northwest and northeast groups (NW+NE).