Genetic linkage of randomly amplified polymorphic DNA (RAPD) markers in sweetpotato

Abstract

RAPD marker analyses were completed on parents and progeny of two sweetpotato [Ipomoea batatas (L.) Lam.] crosses to determine the feasibility of genetic linkage map construction. A total of 100 primers was tested and 96 produced amplified genomic DNA fragments. The average number of polymorphisms per primer was 0.69. A total of 134 polyphorphic markers was observed and 74 (60%) segregated 1 band present: 1 band absent as needed for use in genetic linkage mapping of polyploids. The 60% of RAPD markers that segregated 1:1 shows that genetic linkage mapping of the hexaploid sweetpotato by RAPD marker analysis is feasible. Linkage was determined for all markers that segregated 1:1 and five pairs of linked markers were found. These were the first linked molecular markers found in sweetpotato and they show that construction of a genetic linkage map is feasible. A genetic linkage map will be a valuable tool to assist in genetic improvements.