HIGH-DENSITY MOLECULAR MAP OF SEMIDWARFING GENE, SD-1, IN RICE (ORYZA-SATIVA L.)

High density molecular map of semidwarfing gene, sd-1, was constructed using 178 F-2 plants derived from the cross between the semidwarf nea r-isogenic line and its recurrent parent, japonica cultivar ''Shiokari ''. The total size of the map including nine molecular markers (five R APD and four RFLP markers) and sd-1 was 6.4 cM. The most closely linke d RAPD markers in both sides of sd-1 were OPV1O(500) and OPAE14(1000), and the distance between them was 1.7 cM. Since sd-1 is a recessive g ene, these closely Linked RAPD markers will be very powerful to monito r the gene for large scale selection in breeding program.