PCR detection of the JC7-1 retrotransposon insertion polymorphism. (a) Schematic illustration of RBIP primer design. Arrows indicate the position and direction of the primers used in this study, and target site insertion is represented in green. FLKL X LTRL: A primer set corresponding to the left flanking sequence (forward) and left LTR (reverse); LTRR X FLKR: A primer set corresponding to the right LTR (forward) and the right flanking sequence (reverse); FLKL X FLKR: A primer set corresponding to the left and the right flanking sequences. (b) Presence or absence of JC7-1 restrotransposon marker in twelve jatropha accessions. PCR products are indicated by arrowheads.