雄性不稔을 利用한 水稻 雜種品種 開發 Ⅷ. 統一型 細胞質 雄性不稔系統의 育成 및 育成系統의 組合能力

Development of hybrid rice facilitated by cytoplasmic-genetic male sterility Ⅷ. Breeding of Tongil-type cytoplasmic male sterile lines and their combining ability

This study was pursued to develope the desirable cytoplasmic male sterility(CMS) systems adaptable to Korean situations. The cytoplasmic male sterility of the WA source such as V20A and Z97A CMS lines were transfered to 10 Korean leading cultivars through the backcross procedure. Those newly developed CMS’ were crossed with 7 Korean cultivars known as restorer and examined their combining abilities of grain yield. Twenty cytoplasmic male sterile lines adaptable to Korean situations were developed utilizing two introduced CMS lines, V20A and Z97A which have WA CMS sources. Among the developed CMS lines, Iri342A, Suweon296A and HR1619-2A derived from V20A, and wx498 A, HR1619-5A and wx817A derived from Z97A showed higher combining ability. Among the restorers tested, Milyang57 and Suweon294 showed the greater relative combining ability to the V20A-derived CMS, but Milyang56 showed the greatest to the Z97A-derived CMS. The standard heterosis in the hybrids of V20A-derived CMS lines/restorer ranged from 78.4 to 132.3% with the greatest of HR1619-2A/Suweon294 cross, and 65.1 to 139.0% in the hybrid of Z97A-derived CMS lines/restorer with the greatest of wx498A/Milyan57 cross. Those two crosses yielded of 1100.2 and 1155.9kg/10a, respectively.