Molecular analysis of the SC Program. (A) Backcrossing scheme used to create SC lines from EP lines and an elite donor. Four generations of backcrossing were completed, with selection during each F2 generation for short, photoperiod-insensitive plants. (B) Interpretation of molecular data from donor, SC, and EP lines. SC alleles shared with either the donor or EP lines indicate that introgression has occurred (orange) or not occurred (blue), respectively. SC alleles not found in either parent are unexpected (purple) and were treated as missing data. (C) Genome content of 580 SC lines. Each vertical bar represents a single SC line. Bars are ordered by the percentage of unexpected genotypes. The solid black vertical line indicates a cutoff of 10% unexpected genotypes. (D) Missing and unexpected introgression scores (question marks) were assigned values based on the mean of each flanking marker weighted by its physical distance. (E) A representative example of the introgression maps created for each SC line. The 10 sorghum chromosomes are shown from left to right. The 11th column displays unanchored contigs in the sorghum genome. Long-range linkage disequilibrium in SC lines was exploited to place these contigs on the sorghum physical map.
Thurber et al. Genome Biology 2013 14:R68 doi:10.1186/gb-2013-14-6-r68