Journal Article

A major locus controls local adaptation and adaptive life history variation in a perennial plant

Jansson, Stefan, Ding, Jihua, Tan, Biyue, Robinson, Kathryn M., Ingvarsson, Pär K., Nilsson, Ove, Johansson, Anna, Scofield, Douglas G., Michelson, Ingrid H., Wang, Jing, Nystedt, Björn, Street, Nathaniel R.

2018

Overview

Background The initiation of growth cessation and dormancy represent critical life-history trade-offs between survival and growth and have important fitness effects in perennial plants. Such adaptive life-history traits often show strong local adaptation along environmental gradients but, despite their importance, the genetic architecture of these traits remains poorly understood. Results We integrate whole genome re-sequencing with environmental and phenotypic data from common garden experiments to investigate the genomic basis of local adaptation across a latitudinal gradient in European aspen ( Populus tremula ). A single genomic region containing the PtFT2 gene mediates local adaptation in the timing of bud set and explains 65% of the observed genetic variation in bud set. This locus is the likely target of a recent selective sweep that originated right before or during colonization of northern Scandinavia following the last glaciation. Field and greenhouse experiments confirm that variation in PtFT 2 gene expression affects the phenotypic variation in bud set that we observe in wild natural populations. Conclusions Our results reveal a major effect locus that determines the timing of bud set and that has facilitated rapid adaptation to shorter growing seasons and colder climates in European aspen. The discovery of a single locus explaining a substantial fraction of the variation in a key life-history trait is remarkable, given that such traits are generally considered to be highly polygenic. These findings provide a dramatic illustration of how loci of large-effect for adaptive traits can arise and be maintained over large geographical scales in natural populations.

• Publisher: BioMed Central,Springer Nature B.V,BMC
• Subject: Adaptation / Adaptation, Physiological - genetics / Adaptive traits / Animal Genetics and Genomics / Bioinformatics / Biomedical and Life Sciences / bud set / Colonization / Dormancy / Evolutionary Biology / Evolutionary Genomics / Gene expression / genes / Genes, Plant - genetics / Genetic diversity / Genetic Loci - genetics / genetic variation / Genetic Variation - genetics / Genetics / Genetik / Genome, Plant - genetics / Genomes / Genomic basis / genomics / Glaciation / greenhouses / Human Genetics / Life history / Life History Traits / Life Sciences / Local adaptation / loci / Microbial Genetics and Genomics / Mutation / perennials / Phenology / Phenotype / phenotypic variation / Phenotypic variations / Plant Genetics and Genomics / Plants - genetics / Polygenic inheritance / Population / Populus - genetics / Populus tremula / Principal components analysis / PtFT2 / Reproductive fitness / Scandinavia / Selective sweep / sequence analysis