Analysis of the maternal genome ofElymus nutansfrom the Qinghai‐Tibet Plateau based on chloroplast genomes

Abstract

AbstractElymus nutansis an important forage and ecological restoration herbage in the Qinghai‐Tibet Plateau, which is an allohexaploid species with theStStYYHHgenomes. Previous studies suggested thatPseudoroegneriais the maternal genome donor toE. nutans, but exactly whichPseudoroegneriaspecies is still unknown. Here, we report the complete chloroplast (cp) genome sequence of twoE. nutansfrom the Qinghai‐Tibet and fivePseudoroegneriaspecies. The cp genomes of the seven samples ranged narrowly from 134,924 bp to 135,142 bp in size, comprising inverted repeats of 20,808–20,814 bp, single‐copy regions of 80,536–80,754 bp (LSC) and 12,762–12,772 bp (SSC). It encoded 111 total genes, of which 78 protein‐coding genes, 29 tRNA genes, and four rRNA genes. A comparative cp genome analysis and characteristic junctions ofSt‐containing species revealed that the gene content and organization were conserved, but differences were still found in sequence variation and border regions. Further, the Bayesian inference (BI) phylogenetic tree using the whole chloroplast genome sequence demonstrated thatP. cognatamight be the most likelyStgenome donor ofE. nutansin the Qinghai‐Tibet Plateau, followed byP. strigosa. However, whetherE. nutanshas other maternal genomes still needs further research.