Abstract:Bulked segregant analysis method was conducted to identify RFLP, RAPD and two-primer RAPD markers hnked to the gene for photoperiod-sensitive genic male sterility (PSGMS) in Nongken 58S (Oryza sativa ssp. japonica). A total of 52 RFLP clones, 1040 arbitrary 10-mer oligonucleotide primers and 190 two- primer combinations were screened for their ability to detect polymorphisms between the fertile and the sterile bulks. As a result, RFLP locus G2140 on chromosome 12, a single copy marker, was found to be linked to the PSGMS gene at a distance of 14.1 cM (centimorgan). For RAPD analysis, primer OPAU10 generated a polymorphic product between the two bulks. The polymorphic amplification product was designated as, according to its size (base pairs), OPAU101500. The 1.5 kb fragment was then cloned into plasmid vector and successfully converted to a codominant RFLP marker. Southern hybridization revealed that this clone was a single copy sequence in rice genome and linkage analysis established a close linkageship with RFLP locus G2140 on chromosome 12.