Fig. 5. Structure analysis of Opisopappus taihangensisand Opisopappus longilobus .
a: Total 17 populations divided into OLa, OLb, OTc and OTd groups; b:
The populations of OLa group; c: The populations of OLb group; d: The
populations of OTc group; e: The populations of OTd group.
The EEMS results (Fig. 6) revealed that a significant migration barrier
occurred among populations at the junction of two species along the
Taihang Mountains. Interestingly, the migration channel for the
individuals of the two species was not along with the mountainous areas
but more inclined to the plains in the Taihang Mountains. Additionly,
the populations closest to the migration barrier had much higher
migration rate than the average of whole species. The areas with the
highest genetic diversity tended to be in the areas with low migration
rates. Neverthless, the areas with the highest genetic diversity ofO. longilobus was just in the obstacle areas between O.
taihangensis and O. longilobus .