Population structure and relationship among lines in three association mapping populations (CAP I, CAP II, and CAP III). S: posterior probability of group belonging from STRUCTURE software (Pritchard et al., 2000). C1: light-color, Oregon intermated lines, lines derived by several cycles of intermating progeny derived from crosses among relatively few parents (Kold, Strider, 88Ab536, Excel, Legacy, and Orca); dark-color, non-Oregon intermated lines, lines that are genetically distant to Oregon lines: Hundred, Eight-Twelve, UTWB940119, UTWB94061, UTWB971412, Dicktoo, and Luca. C2: dark-colors (dark-blue and blue) are Oregon CAP I related lines, sister lines with a sib in CAP I; blue are sister lines with a sib in CAP I; dark-blue are Oregon lines derived from crosses with a non-CAP I donor (Bu27); light-colors (white and light-blue) are unrelated germplasm; light-blue are Idaho lines not used as parents of CAP I, Nebraska lines not used as parents of CAP I, and Oregon hooded lines that share one parent (Kold) with CAP I while the other parent (Hoody) is not a parent of CAP I lines; white are other unrelated lines. C3: light-color (Doyce), lines derived from crosses with Doyce; dark-color, Oregon intermated lines.