Phylogenetic relationships of allotetraploid Hordelymus europaeus (L.) Harz (Poaceae: Triticeae)

Phylogenetic analyses of sequence data from two plastid genes (rbcL and ndhF) and two single-copy nuclear genes (DMC1 and EF-G) are used to elucidate the origin of the tetraploid, monotypic Hordelymus europaeus. Previous data have mostly shown an allopolyploid origin of Hordelymus, but very recently it was suggested that Hordelymus is autoploid. The present analysis, including representatives from all basic genome types accepted in the Triticeae, lends support to an alloploid origin. There is substantial support for the progenitor of Psathyrostachys as female genome donor of Hordelymus. Individual nuclear gene trees disagree about the male genome donor, but combined analysis of all data weakly supports the common progenitor of Pseudoroegneria and Henrardia as the male genome donor.