Fig. 1. Generation of a DNA marker associated with sugar beet resistance to root-knot nematode. Bulked DNA samples prepared from susceptible (S1, S2, S3) and resistant (R1, R2, R3) sugar beet plants were subjected to RAPD analysis using the decamer primer pair OPA02 and OPB01. Amplified DNA products were separated on a 1.6% (w/v) agarose gel, stained with EtBr and photographed. The approximately 0.6-kb band seen only in the lanes representing the resistant bulk samples and indicated by the arrow (NEM06) was cloned for sequence analysis and subsequent conversion to a CAPS marker. The 100-bp ladder was included as a size standard (lane M) with the sizes shown listed in kilobasepairs.