The role of dwarf or semi-dwarf gene (s) in increasing rice production is quite well known. However, the existing gene sources for dwarf or semi-dwarf are still very limited. Some dwarf and semi¬dwarf mutants have been produced in Indnesia, e.g. mutant No. A23/PsJ/72K, A13/PsJ/72K. A3/PsJ/72K and C29/PsJ/72K which were derived from Pelita 1/1; mutants No. A227/1. A227/3. B15 and 16-B6 which were originated from A23/PsJ/72K and a dwarf mutant No. M362 induced from "Seratus Malam" upland rice variety. By crossing with Acc 123 which carrying Dee-Geo-Woo-Gen (DGWG) gene, or with a semi-dwarf variety IR 36 which has unidentical gene with DGWG gene, the gene (s) controlled dwarf or semi-dwarf characters in the mutant. were studied through the reflection occured in F 1 phenotype. The result obtained showed that there were two genes identified were not identical with DGWG gene, viz. a semi¬dwarf gene of A227/3 and a dwarf gene of M362. The dwarf gene ofM362.was also not iden¬tical with the semi-dwarf gene of IR 36. Although dwarf gene of C29/PsJ/72K was not iden¬tical with the semi-dwarf gene of IR 36 or the dwarf gene of M362, it has not been proved whether it is also not identical with DGWG gene. Riyanti Sumanggono
