The complete chloroplast genome sequences of five Miscanthus species, and comparative analyses with other grass plastomes

Miscanthus has been considered as potentially high-yielding biomass crop with the low-nutrient requirements, high capability of Carbon mitigation and water-use efficiency. Miscanthus species have restricted to investigate functional genomics of their large genome size, which leads to challenges to genomics-aided crop improvement. Sequencing of the plastid genomes of Miscanthus is one of complementary tool making it available for genetic researches. The complete chloroplast (cp) genomes of five Miscanthus species were sequenced using Illumina sequencing. Comparisons between the five chloroplast genome sequences revealed their conservation in gene content and order, including the IR/SC boundaries. However, some hotspots in coding regions and intergenic regions also occurred. Specifically a 13 bp deletion in the intergenic region of rps16-trnQ and a 17 bp deletion in rps4-trnT are shared by Miscanthus lutarioriparius L., Miscanthus sacchariflorus N. and Miscanthus × giganteus. In addition, a 39 bp deletion in trnL-trnF is shared by Miscanthus sinensis A. and Miscanthus floridulus W.. Comparisons of complete chloroplast genome of Miscanthus lutarioriparius to five published grass chloroplast genomes also reveal several hotspot regions with high polymorphism. Phylogenetic analysis based on complete chloroplast genomes and coding sequences of 77 protein genes suggest a sister relationship between the Eumiscanthus clade and the Triarrhena clade. This report is the first comprehensive comparative analyses on Miscanthus species cp genome combining other published grass chloroplast genomes. The availability of these results will supplement valuable genetic information and framework for further phylogeography, population genetics and plastid genetic engineering researches in Miscanthus.sp.