Genetic diversity and hybridization of Japanese Miscanthus sinensis and Miscanthus sacchariflorus. Miscanthus

Miscanthus is a genus of perennial grasses native to east Asia and is emerging as an important crop for the lignocellulosic bioenergy industry. To enable breeding of improved biomass cultivars, we used restriction site-associated DNA sequencing (RAD-seq) to characterize the genetic diversity of diploid M. sinensis and tetraploid M. sacchariflorus native to Japan. In addition to identifying triploid and tetraploid hybrids between these two species, we detected a large amount of introgression from M. sinensis to M. sacchariflorus, such that very few individuals could be considered pure M. sacchariflorus. Knowledge of this introgression will be important when choosing parent individuals to use in the creation of new M. xgiganteus (M. sacchariflorus x M. sinensis) hybrid cultivars. We also found rare M. sinensis individuals with introgressed DNA from M. sacchariflorus, primarily in northern Japan. Lastly, we examined the spatial genetic structure of M. sinensis across Japan, which will guide germplasm collection efforts.

芒草属（Miscanthus）为原产于东亚的多年生草本植物类群，正日益成为木质纤维素生物能源产业的重要栽培作物。为培育性状更优良的生物质品种，我们借助限制性位点相关DNA测序（restriction site-associated DNA sequencing, RAD-seq）技术，对日本原生的二倍体芒（M. sinensis）与四倍体荻（M. sacchariflorus）的遗传多样性开展了表征分析。除成功鉴定出这两个物种间的三倍体与四倍体杂交种外，我们还检测到大量由芒向荻的基因渐渗事件，以至于几乎无个体可被认定为纯合荻。此类基因渐渗的相关研究认知，在筛选用于培育新型巨芒草（M. xgiganteus，即M. sacchariflorus × M. sinensis）杂交品种的亲本时，具备重要指导价值。此外我们还发现了少量携带荻源渐渗DNA的芒个体，这类个体主要分布于日本北部地区。最后，我们解析了日本境内芒的空间遗传结构，该研究结果可为后续种质资源收集工作提供科学指引。