Towards high-biomass yielding bioenergy crop Silphium perfoliatum L.: phenotypic and genotypic evaluation of the cultivated populations

Cup plant (Silphium perfoliatum L.), a perennial from the family Asteraceae, represents a promising alternative to silage maize as an energy crop for biogas production. So far, there have been almost no breeding attempts for the cup plant, and all field experiments showing its high biomass yield were conducted by using only a few cultivated populations of unclear ancestry. Genetic relationships among 96 individual cup plants of fourteen different origins were estimated using tunable genotyping by sequencing (tGBS) technology (Data2Bio®). Fifty-five of these plants belonging to 5 cultivated cup plant populations were analysed in details for both their genetic and phenotypic characteristics. Genetic structure and phylogeny analyses revealed that five populations belong to the same gene pool and share a common ancestry. Four out of five populations demonstrate a low genetic differentiation probably due to sparse breeding initiatives or seed exchange between origins, whereas the fifth accession represents a clear example of population stratification. Genome-wide association study identified several significant phenotype-genotype associations for six morphological traits, which, if validated, might be useful in marker-assisted selection of cup plant.