Introgression analysis of an interspecific hybrid population in peanuts (Arachis hypogaea L.) using RFLP and RAPD markers

Forty-six introgression lines (F10C9) from a cross between Arachis hypogaea L. (2n = 4x = 40) and A. cardenasii Krapov. &W.C. Gregory (2n = 2x = 20) were analyzed for the introgression of A. cardenasii chromosome segments. Seventy-three RFLP probes and 70 RAPD primers, expressing from one to four A. cardenasii-specific bands, were used to evaluate the set of introgression lines. Thirty-four RFLP probes and 45 RAPD primers identified putative A. cardenasii introgressed chromosome segments in one or more lines. Introgressed segments were detected by RFLP analysis in 10 of the 11 linkage groups; the smallest introgressed fragments were detected by single RFLP markers and the largest were detected by three or four adjacent markers and represented introgressed segments of 30–40 cM. Similar results were obtained with RAPD markers, although markers detecting introgressed fragments could not be placed on the peanut linkage map. Introgression into both A. hypogaea genomes was detected and its implication in breeding for disease resistance is discussed.Key words: peanut, Arachis hypogaea, Arachis cardenasii, RFLPs, RAPDs, introgression, reciprocal recombination, translocation, alien gene transfer, wide cross.