MAPPING THE SW-5 LOCUS FOR TOMATO SPOTTED WILT VIRUS-RESISTANCE IN TOMATOES USING RAPD AND RFLP ANALYSES

The Sw-5 locus confers dominant resistance to tomato spotted wilt viru s (TSWV). To map the location and facilitate the identification of mar kers linked to Sw-5 we developed a pair of near-isogenic lines (NILs) and an F-2 Lycopersicon esculentum x L. pennellii population segregati ng for resistance to TSWV. DNA from the NILs was analyzed using 748 ra ndom 10-mer oligonucleotides to discern linked molecular markers using a random amplified polymorphic DNA (RAPD) approach. One random primer (GAGCACGGGA) was found to produce a RAPD band of about 2200 bp that d emonstrates linkage to Sw-5. Data from co-segregation of resistance an d restriction fragment length polymorphisms (RFLPs) in a F-2 interspec ific population position Sw-5 between the markers CT71 and CT220 near the telomere of the long arm of chromosome 9.