Abstract
In the Alps phylogeographic studies indicate for small insect-pollinated herbs that climatic fluctuations caused significant population migrations and fragmentations into glacial refugia at the periphery of the Alps. Here we investigate whether this holds also for wind-pollinated and -dispersed species. We therefore analysed the phylogeographic pattern (nuclear and chloroplast dataset) of a clade of the four species of the Helictotrichon parlatorei species group (Poaceae) endemic to the Alps. In contrast to earlier findings for small insect-pollinated herbs no clear barriers to gene flow could be detected in this species group. Instead a few haplotypes are widespread across the entire Alpine region. While the complete absence of a phylogeographic structure in the plastid dataset hints towards very efficient long distance seed dispersal, the moderate phylogeographic structure in the nuclear dataset indicates at least some spatial restriction to pollen dispersal. Rare haplotypes cluster solely in the Western and Southern central Alps and thereby suggest this to be the area of origin for the H. parlatorei species group from where expansion occurred following the presence of calcareous bedrock into the Eastern Alps. We thus conclude that the inclusion of taxa with complementary life-history traits is vital in understanding the glacial history of the Alpine flora.
Highlights
The current distribution and intraspecific genetic structure of alpine species is thought to be mainly shaped by climatic conditions of the past
In total 106 At103-sequences (81 Helictotrichon parlatorei, 7 H. setaceum subsp. setaceum, 8 subsp. petzense and 10 H. sempervirens) were obtained yielding an alignment of 320bp with 7 SNPs. These combined into 10 haplotypes (8 H. parlatorei, 3 H. setaceum subsp. setaceum, 2 subsp. petzense and 2 H. sempervirens) (Table 2)
The most frequent and widely distributed haplotype was H7 found in all four species and across the entire Alps except for the central northern flank. It was quite dominant in the eastern region in H. parlatorei and in the Western Alps in H. setaceum subsp. setaceum and H. sempervirens
Summary
The current distribution and intraspecific genetic structure of alpine species is thought to be mainly shaped by climatic conditions of the past. Climatic fluctuations caused significant population migrations and fragmentations or even extinctions [1,2,3] and thereby repeatedly provoked allopatric speciation [4, 5]. A comparison of phylogeographic patterns with geological and palaeoenvironmental data demonstrates that glacial refugia were located during maximal glaciation along the southwestern, southern, eastern and northern border of the Alps [6]. Additional glacial refugia were present in central alpine areas, where plants from the alpine belt survived the last glaciation on ice-free mountain tops. The long-term glacial survival in isolated refugia in the periphery of the European Alps likely caused genetic drift, which explains the strong spatial genetic.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
