Location of HWC2 on rice chromosome 4. a Approximate location of the C1112 and C1016, initially used DNA markers for recombinants around the HWC2 locus from the cross between Nipponbare and Kasalath, on the high-density linkage map of chromosome 4 modified from Harushima et al. (1998). b Fine mapping of HWC2 using the cross between Nipponbare and Kasalath. A total of 50 recombinants between two DNA markers, 93*14.1 and S13714, were crossed to Jamaica and were analyzed for the order of HWC2 and the internal DNA markers. c The 19-kb region containing HWC2, narrowed down by using all the cross combinations in Table 2, on the rice BAC clone OSJNBa0053K19 and positions of ORFs predicted using RiceGAAS (Sakata et al. 2002).