Parents of the M. sinensis mapping population. A full sib (F1) population was produced by reciprocally crossing two ornamental M. sinensis accessions, "Grosse Fontaine" (GF) and "Undine" (UN). The parents of the mapping population were propagated from rhizomes taken from two individual plants, UN (panel A, plant location SF20) and GF (panel B, plant location SF5), established by Emily Heaton in the spring of 2001 at the SoyFACE plot located at the Crop Sciences Research and Education center, on the University of Illinois campus. The photographs of GF and UN were taken on July 11 2011. Panel B shows the individual GF and UN plants used to make the F1 mapping population, flowering in the greenhouse (photograph taken on Dec 14th 2009). Phenotypic measurements reported in Additional file 1: Table S1, were taken on these two plants at maturity. Panel C shows the full sib F1 mapping population in August 2010 at the University of Illinois Energy Farm. This population was established in the spring of 2010.