DISCUSSION
Our
population genetic analyses of the A. viridiflora complex within
its main range across Northern China suggest a paraphyletic divergence
scenario of the species complex with significant phenotypic divergence.
These lineages show moderate levels of genetic differentiation and
diverged from each other 168 to 239 Kya, a timing in the Middle
Pleistocene that the most important climate transition has occurred,
namely, the “mid-Brunhes transition” (MBT, ~400 Kya)
(Ao et al., 2020). The results further indicate that both geographic
isolation and selective pressures via environmental factors have
contributed to the observed lineage differentiation. In the following,
these findings will be discussed in more detail.