Origin of the wheat B-genome chromosomes conferred by RNA-seq analysis of leaf transcripts in the section Sitopsis species of Aegilops

Common wheat (Triticum aestivum L., genome constitution AABBDD), one of the major crops, is an allohexaploid species, derived from allopolyploid speciation through interspecific crossing between cultivated tetraploid wheat Triticum turgidum L. (AABB) and its diploid relative Aegilops tauschii Coss. (DD). However, the B genome origin has been still under discussion despite of extensive efforts during the past few decades. To clarify the origin of the wheat B-genome chromosomes, RNA sequencing of leaf transcripts in the section Sitopsis species of Aegilops was performed. We estimated phylogenetic relationship of Sitopsis species and genetic divergence between them based on single nucleotide polymorphisms derived from RNA sequencing data.