Southern hybridization analysis. Membranes that are essentially the same as shown in Figure 2 were subjected to Southern hybridization using EST clones as probes. Lane a, Taq I-digested Columbia genomic DNA (500 ng), lane b, Taq I-digested Landsberg erecta genomic DNA (500 ng) with a single copy adenovirus-2 DNA, lane c, control IGCR DNA sample (300 ng), and lane d, IGCR sample (300 ng). The numbers shown on each panel are those of the clones shown in panel B in Figure 3. When restriction fragment length polymorphism (RFLP) DNA bands were clearly shown, the genomic regions corresponding to the RFLP bands for both Columbia and Landsberg erecta strains were PCR-amplified and the products were sequenced. The size (bp) of each pair of the RFLP fragments is indicated.