Genomics and Breeding of Miscanthus

Miscanthus is an important bioenergy crop, and also a genetic resource for improving sugarcane.  Recent studies of Miscanthus genomics have provided valuable guidance for our breeding efforts.  Molecular genetic confirmation that production fields of the key bioenergy Miscanthus species, M. ×giganteus, have been planted almost entirely to one genotype has spurred us to 1) focus our research on its parental species, M. sinensis and M. sacchariflorus, and 2) breed new M. ×giganteus genotypes.  For M. sinensis, analyses of population structure have revealed patterns of diversity and differentiation throughout much of its native range in eastern Asia, suggesting new opportunities for enhancing heterosis in M. ×giganteus.  In Japan, where the agriculturally valuable cultivar of M. ×giganteus originated, we found that bidirectional but asymmetric introgression between diploid M. sinensis and tetraploid M. sacchariflorus has resulted in tetraploid hybrid swarms, an insight that will guide our selection of M. sacchariflorus parents.  With genome wide association studies and biparental mapping populations, we have begun to identify genetic markers associated with key agronomic traits, a first step towards improving breeding efficiency via marker-assisted selection.  Especially intriguing for the improvement of sugarcane, we have found Miscanthus genotypes with strong resistance to root lesion nematodes (Pratylenchus spp.), a serious pest to which sugarcane lacks resistance.  With these new insights in-hand and more undoubtedly on the way, Miscanthus breeding has a promising future.