Dated tribe-wide whole chloroplast genome phylogeny indicates recurrent hybridizations within Triticeae

BMC Evolutionary Biology

Research Article

Nadine Bernhardt¹  Jonathan Brassac¹  Frank R. Blattner²  Benjamin Kilian³ 

[1] Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany;Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany;German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany;Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany;Present address: Crop Trust, Bonn, Germany;

关键词: Hybridization;    Whole chloroplast genome;    Phylogeny;    Next-generation sequencing;    Divergence times;    Triticeae;    Wheat;    Triticum;    Aegilops;    Psathyrostachys;   

DOI  :  10.1186/s12862-017-0989-9

 received in 2017-01-11, accepted in 2017-06-03,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundTriticeae, the tribe of wheat grasses, harbours the cereals barley, rye and wheat and their wild relatives. Although economically important, relationships within the tribe are still not understood. We analysed the phylogeny of chloroplast lineages among nearly all monogenomic Triticeae taxa and polyploid wheat species aiming at a deeper understanding of the tribe’s evolution. We used on- and off-target reads of a target-enrichment experiment followed by Illumina sequencing.ResultsThe read data was used to assemble the plastid locus ndhF for 194 individuals and the whole chloroplast genome for 183 individuals, representing 53 Triticeae species and 15 genera. We conducted Bayesian and multispecies coalescent analyses to infer relationships and estimate divergence times of the taxa. We present the most comprehensive dated Triticeae chloroplast phylogeny and review previous hypotheses in the framework of our results. Monophyly of Triticeae chloroplasts could not be confirmed, as either Bromus or Psathyrostachys captured a chloroplast from a lineage closely related to a Bromus-Triticeae ancestor. The most recent common ancestor of Triticeae occurred approximately between ten and 19 million years ago.ConclusionsThe comparison of the chloroplast phylogeny with available nuclear data in several cases revealed incongruences indicating past hybridizations. Recent events of chloroplast capture were detected as individuals grouped apart from con-specific accessions in otherwise monopyhletic groups.

【 授权许可】

CC BY   
© The Author(s). 2017