<i>ERECTA</i> Corresponds to the Petal Shape Quantitative Trait Locus (QTL) <i>CL-S1</i> on Chromosome II.

<p>(<b>A</b>) Chromosome II diagram showing introgression lines and mutants used for QTL fine mapping. The Stepped Aligned Inbred Recombinant Strain (STAIRS) introgression lines are numbered and their L<i>er</i> -0 introgressions are drawn to scale in black and the otherwise entirely Columbia (Col-4) background is shown in white. The location of the <i>CL-S1</i> 2-LOD interval is drawn to scale with the boundaries marked as black horizontal lines, and the <i>er</i> mutants used, such as <i>er-105</i>, have an <i>er</i> mutation in an otherwise entirely Columbia (Col-0) background (apart from L<i>er</i>-0 which is an <i>er</i> mutant in a Landsberg background). (<b>B</b>) Histogram showing shape measurements of stage 13 petals using STAIRS, natural isolates, and <i>er</i> mutants. Error bars indicate 95% confidence intervals. For each line a minimum of 20 petals were scored. (<b>C</b>) Stage 13 representative petal images. Scale bar = 1 mm.