DOI: 10.5061/dryad.p5hqbzkpd
title: Localized environmental heterogeneity drives the population differentiation of two endangered and endemic Opisthopappus Shih species

description: Background: Climate heterogeneity not only indirectly shapes the genetic
 structures of plant populations, but also drives adaptive divergence by
 impacting demographic dynamics. The variable localized climates and
 topographic complexity of the Taihang Mountains make them a major natural
 boundary in Northern China that influences the divergence of organisms
 distributed across this region. Opisthopappus is an endemic genus of the
 Taihang Mountains that includes only two spatially partitioned species
 Opisthopappus longilobus and Opisthopappus taihangensis. For this study,
 the mechanisms behind the genetic variations in Opisthopappus populations
 were investigated. Results: Using SNP and InDel data coupled with
 geographic and climatic information, significant genetic differentiation
 was found to exist either between Opisthopappus populations or two
 species. All studied populations were divided into two genetic groups with
 the differentiation of haplotypes between the groups. At approximately
 17.44 Ma of the early Miocene, O. taihangensis differentiated from O.
 longilobus under differing precipitation regimes due to the
 intensification of the Asian monsoon. Subsequently, intraspecific
 divergence might be induced by the dramatic climatic transformation from
 the mid- to late Miocene. During the Pleistocene period, the rapid uplift
 of the Taihang Mountains coupled with violent climatic oscillations would
 further promote the diversity of the two species. Following the
 development of the Taihang Mountains, its complex topography created
 geographical and ecological heterogeneity, which could lead to
 spatiotemporal isolation between the Opisthopappus populations. Thus the
 adaptive divergence might occur within these intraspecific populations in
 the localized heterogeneous environment of the Taihang Mountains.
 Conclusions: The localized environmental events through the integration of
 small-scale spatial effects impacted the demographic history and
 differentiation mechanism of Opisthopappus species in the Taihang
 Mountains. The results provide useful information for us to understand the
 ecology and evolution of organisms in the mountainous environment from
 population and species perspective.
description: Our study was conducted in
 accordance with the laws of the People's Republic of China, and field
 collection was approved by the Chinese Government. Subsequently, the total
 genomic DNA was extracted by using the modified 2 × CTAB method across 23
 populations including 11 populations of <i>O. longilobus</i>
 and 13 populations of <i>O. taihangensis</i>. The primer
 source and PCR procedure proceeded as described detailedly in manuscript.
 After sequences alignment, 120 concatenating sequences generated 75
 haplotypes. The total length of the haplotype was 1921 bp, which contained
 1870 monomorphic sites and 51 polymorphic sites. Therein, we would upload
 the haplotype datasets, including the total number of sites (1921 bp) and
 the polymorphic sites (51 bp) for data sharing.