Colonization history of Scots pine in Eastern Europe and North Asia based on mitochondrial DNA variation

Abstract

During Quaternary glaciations the ranges of Northern Eurasia forest biota species periodically experienced contraction followed by subsequent recolonizations in the interglacial intervals. However, unlike the broadleaf trees of temperate forests, taiga species seem not fully retreated to southern regions in unfavorable periods and possibly survived at mid-latitudes in multiple refugia. It is supported by this study of genetic variation of three mitochondrial DNA markers in 90 populations of Scots pine (Pinus sylvestris) located from Eastern Europe to Eastern Siberia. Geographic distribution of nine mitochondrial haplotypes (mitotypes) demonstrated the split between western and eastern populations approximately along the 38 th meridian. Genetic diversity in the western part was significantly higher than in the eastern one. 2 Six haplotypes were western-and two eastern-specific. One haplotype was common in both regions, but in the eastern part it occurred only in the South Urals and adjacent areas. The structure of the mitotype geographical distribution supports the hypothesis of the post-glacial recolonization of the studied territory from the European and Ural refugia.

Sequence Capture of Mitochondrial Genome with PCR-Generated Baits Provides New Insights into the Biogeography of the Genus Abies Mill.

“…Both the isolated position of the island firs in the mtDNA tree ( Figure 2 ) and the age of separation from other American clades significantly contradict the previous assumption that the island species retain mtDNA inherited from their American ancestor [ 18 ]. At the same time, our hypothesis that significant difference in island species mtDNA from the mtDNA of other American firs resulted from the introgression of genes from Asian firs is not supported by the ABBA-BABA test.…”

“…To estimate the divergence time, a penalized likelihood approach implemented in treePL [ 49 ] was employed. The calibration was carried out similarly to [ 18 ]: the age priors were applied to four clades: (1) for Pinaceae crown group, the minimum age of 155 Mya (based on the one of the oldest Pinaceae fossils (seed cone of Eathiestrobus mackenziei ) [ 50 ]) and the maximum age of 308.5 Mya (in accordance with unambiguous coniferous fossils in the Late Carboniferous) were used [ 51 ]; (2) for the Abies - Keteleeria divergence, the minimum age of 45.5 Mya was based on the earliest macrofossils clearly belonging to Abies sp. (vegetative axes, winged seeds, needles [ 52 ]) and the maximum age of 113.8 Mya corresponded to the low boundary of the Aptian age, when the oldest known fossil pollen of Abies was found [ 53 , 54 , 55 ]; (3) for the Abies crown, the minimum age of 13.5 Mya corresponded to the age of the earliest macrofossils that indubitably represent a species, related to the extant A. bracteata (D. Don) A. Poit (cone bracts, needles and seeds, [ 56 ]) while the maximum age was considered to be 45.5 Mya; (4) for the divergence of Pinoideae subfamily ( Larix - Picea split), the minimum age of 133 Mya (the oldest record of Pinus [ 57 ]), whereas the maximum age of 308.5 Mya [ 51 ] were used.…”

Phylogeography of Scots pine in Europe and Asia based on mtDNA polymorphisms

“…Population structure assessments using maternally inherited seed‐dispersed mitochondrial (mtDNA) markers have been largely limited to variations in a few polymorphic markers, mostly the nad1 and nad7 regions (Sinclair et al, 1998; Sinclair et al, 1999; Soranzo et al, 2000; Cheddadi et al, 2006; Naydenov et al, 2007; Pyhäjärvi et al, 2007). However, due to the low spatial resolution of these markers, population structure has only been resolved at a broad scale (Soranzo et al, 2000; Naydenov et al, 2007; Pyhäjärvi et al, 2008; Wójkiewicz et al, 2016a; Dering et al, 2017; Semerikov et al, 2018; Zimmer & Sønstebø, 2018). Southern refugial populations were certainly present and are consistently evident in marker data sets as locations of distinctive mitotypes in Iberia, Italy, and Turkey (Cheddadi et al, 2006; Dering et al, 2017; Donnelly et al, 2017; Semerikov et al, 2020).…”

Divergent patterns between phenotypic and genetic variation in Scots pine

“…In contrast to the weak structure in the nuclear genome, mitochondrial DNA markers have shown distinct differentiation in Scots pine from western Europe to eastern Russia ( Naydenov et al., 2007 ; Dering et al., 2017 ). Mitochondrial DNA markers are maternally inherited through seeds and can often reveal otherwise hidden demographic components due to the low dispersal ability of seeds ( Pyhäjärvi et al., 2008 ; Semerikov et al., 2018 ). Unfortunately, the resolution so far is low from the detected mitochondrial variation in Scots pine, nonetheless two distinct mitotypes have been found in Fennoscandia ( Dering et al., 2017 ), and the pattern is inconclusive as to whether a refugium existed in northern Scandinavia under the LGM ( Kullman, 2008 ; Parducci et al., 2012 ).…”