Informace o publikaci

Mesopolyploidy as a taxonomic clade marker for Brassica and relatives (tribe Brassiceae)

Autoři	THOMAS Shawn K ABRAHAMS R Shawn KICK Daniel Robert WALDEN Nora CONANT Gavin MCKAIN Michael R AN Hong ARIAS Tatiana EDGER Patrick P HARKESS Alex HENDRIKS Kasper P KOCH Marcus A LENS Fredric LYSÁK Martin MCALVAY Alex MUMMENHOFF Klaus AL-SHEHBAZ Ihsan A WASHBURN Jacob D PIRES J Chris
Rok publikování	2026
Druh	Článek v odborném periodiku
Časopis / Zdroj	Annals of Botany
Fakulta / Pracoviště MU	Středoevropský technologický institut
Citace
www	https://doi.org/10.1093/aob/mcaf170
Doi	https://doi.org/10.1093/aob/mcaf170
Klíčová slova	Whole-genome duplication; phylogenomics; mustard crops; Brassica; Brassicaceae; Cruciferae
Popis	Background and Aims: Whole-genome duplications (WGDs) are rampant in flowering plant genomes. Within Brassicaceae, the genus Brassica (including crop mustards) and relatives (tribe Brassiceae) are hypothesized to share an ancient mesohexaploidy, or whole-genome triplication (WGT), resulting from two WGD events (Br-alpha WGT). However, the phylogenetic boundaries of the Br-alpha WGT remain unknown. Methods: We use phylogenomic assessments and divergence time analyses to place and date the Br-alpha WGT. We see conflicting topologies among the plastid and nuclear trees putatively due to polyploidy, hybridization and reticulate evolution. Despite this, we find tribe Brassiceae to be monophyletic in both trees. Key Results: As currently circumscribed, tribe Brassiceae does not share the Br-alpha WGT. The sister clade to the rest of the tribe, containing the genera Orychophragmus and Sinalliaria, show no evidence of the Br-alpha WGT. Based on this placement, divergence time analyses indicate that the Br-alpha WGT would have occurred between 12.1 and 10.7 million years ago. Conclusions: We propose a new taxonomic revision for the tribe Brassiceae based on the shared characteristics of the Br-alpha WGT. This presents a stable characteristic for the tribe, which was not the case in previous taxonomies based on morphological characters. These findings help clarify the history of the mustard crops and their relatives and resolve long-standing issues with the circumscription of the tribe Brassiceae.