A RAPD-based Linkage Map of Peanut Based on a Backcross Population Between the Two Diploid Species Arachis stenosperma and A. cardenasii

A molecular linkage map based on an interspecific diploid backcross population [Arachis stenosperma × (A. stenosperma × A. cardenasii)] was constructed utilizing RAPD and RFLP markers. One hundred sixty-seven RAPD loci and 39 RFLPs were mapped to 11 linkage groups, covering a total genetic length of 800 cM. Clusters of 2 to18 markers were observed in most linkage groups. Twenty seven percent of the markers showed segregation distortion and mapped to four regions. Thirty-nine RFLP markers shared with a previously published linkage map, based on an A. stenosperma × A. cardenasii F2 population, and six RAPD markers were used to establish correspondence between maps and to compare recombination frequencies between common markers. A generalized reduction in the recombination fraction was observed in the backcross map compared to the F2 map. All common markers mapped to the same linkage groups and mostly in the same order in both maps.