Figure 2. Models for population structure at three steps of maize selection history: open pollinated varieties, also called landraces (seven groups), first cycle inbreds (five groups), and whole inbred panel (five groups). Groups for each panel are represented by colors as indicated at the bottom of the figure. For the inbred panels, each inbred line is represented by a vertical line divided into colored segments, the length of which indicates the proportion of the genome attributed to the different groups. For the landrace panel, each population is represented by the mean proportions estimated for the five inbred lines simulated to represent it. Plain arrows stand for filiation relationship between clusters and have been established on the basis of either STRUCTURE assignments (in the joint study of landraces and first cycle inbreds) or genetic distances between groups of inbred line panels. Dotted arrows indicate lower contributions (less than three inbred lines with a high genome proportion (>0.80) attributed to a group obtained in the STRUCTURE joint analysis of landraces and first cycle inbred lines). From (Camus-Kulandaivelu et al., 2006).