Postglacial range expansion and the role of ecological factors in driving adaptive evolution of Musa basjoo var. formosana

Abstract

Genetic variation evolves during postglacial range expansion of a species and is important for adapting to varied environmental conditions. It is crucial for the future survival of a species. We investigate the nuclear DNA sequence variation to provide evidence of postglacial range expansion of Musa basjoo var. formosana, a wild banana species, and test for adaptive evolution of amplified fragment length polymorphic (AFLP) loci underlying local adaptation in association with environmental variables. Postglacial range expansion was suggested by phylogeographical analyses based on sequence variation of the second intron of copper zinc superoxide dismutase 2 gene. Two glacial refugia were inferred by the average F ST parameter (mean F ST of a population against the remaining populations). Using variation partitioning by redundancy analysis, we found a significant amount of explained AFLP variation attributed to environmental and spatially-structured environmental effects. By combining genome scan methods and multiple univariate logistic regression, four AFLP loci were found to be strongly associated with environmental variables, including temperature, precipitation, soil moisture, wet days, and surface coverage activity representing vegetation greenness. These environmental variables may have played various roles as ecological drivers for adaptive evolution of M. basjoo var. formosana during range expansion after the last glacial maximum.

The Contribution of Neutral and Environmentally Dependent Processes in Driving Population and Lineage Divergence in Taiwania (Taiwania cryptomerioides)

“…The differences in floristic compositions between habitats of Taiwania lineages suggest that landscape heterogeneity might have contributed to the large unaccounted genetic and epigenetic variations found using variation partitioning (Table 4 ). In addition, genetic and epigenetic variations of Taiwania may also be influenced by historical biogeographical processes (Ricklefs and Jenkins, 2011 ; Chen et al, 2017 ; Herrera et al, 2017 ; Richards et al, 2017 ).…”

“…NDVI is a measure of surface coverage activity and has been shown to be correlated with intraspecific (Huang et al, 2015a ; Chen et al, 2017 ) and interspecific adaptive divergence (Nakazato et al, 2010 ; Huang et al, 2015a ). NDVI represents the level of vegetation greenness, a proxy to photosynthetic activity, and may be an influential factor acting on epigenetic variation (uP14MH_102) in response to interactions with other species in a local ecological community (Violle et al, 2012 ).…”

“…Selection driven by ecological factors acting on genetic variation of DNA sequences is of major importance in evolutionary biology (Schluter, 2001 , 2009 ). DNA sequence variation revealed by amplified fragment length polymorphism (AFLP) has been found to be closely associated with environmental conditions in shaping population adaptive divergence of many plant species (e.g., Fang et al, 2013 ; Huang et al, 2015a , b ; Santiso et al, 2016 ; Yang et al, 2016 ; Chen et al, 2017 ). There is an increasing interest in investigating environmentally dependent epigenetic variation in natural populations, which is also important for understanding the potential for adaptation of populations and species that are enduring rapid global environmental changes (Bossdorf et al, 2008 ; Johnson and Tricker, 2010 ; Alonso et al, 2015 ; Huang et al, 2015b ; Villota-Salazar et al, 2016 ).…”

Adaptive Genetic Divergence Despite Significant Isolation-by-Distance in Populations of Taiwan Cow-Tail Fir (Keteleeria davidiana var. formosana)

“…Population structure of species may exhibit a pattern of IBE due to range expansion since colonization of their ancestral species and lead to locally adapted lineages associated with environmental heterogeneity (Holt, 2003 ; Schlotfeldt and Kleindorfer, 2006 ; Huang et al, 2015 ). Post-glacial expansion since the Last Glacial Maximum (LGM, 26.5–19.0 thousand years ago) (Lambeck and Chappell, 2001 ) may have also played a role in invoking locally adapted variants correlated with ecological complexity and climate change (Aitken et al, 2008 ; Chen et al, 2017 ).…”

Demographic history and adaptive synonymous and nonsynonymous variants of nuclear genes in Rhododendron oldhamii (Ericaceae)

“…These results suggest that there were exon variants, particularly the frequent synonymous variants, played important roles in adapting to higher values of BIO1, WSmean, and RH, and individuals possessed these exon variations inhabiting the flatter, with smaller environmental variance, rather than the steep mountain slopes. Evidence of temperature plays an important role as an ecological driver either for adaptive genetic or epigenetic variation has been widely detected for diverse plant species distributed in different parts of the world 5,[66][67][68][69][70] . Slope as a topological factor can act as a heat source in the day time and the surface temperature become warmer than the free atmosphere 71,72 .…”