Analysis of phylogenetic relationships among Triticeae grasses II - The (allo)polyploid genera

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The grass tribe Hordeeae (till recently called Triticeae) includes the important cereals barley, rye and wheat, together with fodder grasses and ecologically important taxa of open landscapes. Thus, the taxa provide staple food for large parts of the human population. Although hypotheses about relationships of the different genera and species were erected for more than a century the phylogeny of the group is still not finally resolved. During the first project period we developed a DNA capture design that allows us to obtain and next-generation sequence >320 nuclear genes, uniformly distributed on the seven chromosomes of the members of the tribe. We used these loci to clarify species relationships of diploid Hordeeae taxa. Now we will analyze the polyploid taxa, to clarify mode of evolution and involvement of the different parental species of the allopolyploid genera of Hordeeae. A final phylogeny of the tribe will be obtained by sequence capture of the target loci, sequencing of pooled libraries on the Illumina platform, phasing of homoeologs, and coalescent-based phylogenetic analyses of the polyploid-derived sequences together with such already obtained from the diploid taxa. Our data will not only provide a phylogeny of all genera of Hordeeae but allow also insights in evolutionary dynamics of genome parts as well as estimation of the amount of introgression that is going on among Hordeeae taxa.