Molecular phylogeny of tetraploid Elymus species revealed by the DMC1 gene

Abstract

Although the relationship of genera of Triticeae has been analyzed in many previous studies, polyploid genera have not been as extensively studied as diploid ones within a phylogenetic framework. The present study focuses on tetraploidy of Triticeae Elymus species, which are all polyploid and distributed worldwide. Five basic genomes (St, H, Y, P, and W) in different combinations have so far been found in the Elymus. To estimate the phylogenetic relationship of tetraploid Elymus with genome content of StH or StY, data from nuclear single copy gene DMC1 (disrupted meiotic cDNA) of 39 tetraploid Elymus accessions and their potential genome donor diploid species were used. For StH species involved, the result revealed close relationship of Pseudoroegneria and Hordeum to Elymus StH species by multiple origins and recurrent hybridization. For StY species involved, it is suggested that St and Y genomes may be related on this locus. A direct contribution from P genome to StY genome through introgression still remains a possibility.