Construction of a reference linkage map for melon

A map of melon (Cucumis melo L.) with 411 markers (234 RFLPs, 94 AFLPs, 47 RAPDs, 29 SSRs, five inter-SSRs, and two isozymes) and one morphological tr ait (carpel number) was constructed using the F-2 progeny of a cross betwee n the Korean accession PI161375 and the Spanish melon type 'Pinyonet Piel d e Sapo'. RFLPs were obtained using 212 probes from different genomic and cD NA melon libraries, including 16 Arabidopsis ESTs, 13 Cucumis known genes, and three resistant gene homologues. Most loci (391) mapped to 12 major lin kage groups, spanning a total genetic distance of 1197 cM, with an average map interval of 3 cM/marker. The remaining 21 loci (six RAPDs and 15 AFLPs) were not linked. A majority (66%) of the markers were codominant (RFLPs, S SRs, and isozymes), making them easily transferable to other melon crosses. Such markers can be used as a reference, to merge other melon and cucumber maps already constructed. Indeed, some of them (23 SSRs, 14 RFLPs, one iso zyme, and one morphological trait) could act as anchor points with other pu blished cucurbit maps.