Abstract

The chloroplast DNA (cpDNA) genetic diversity in Oryza sativa and different types of cytoplasmic male sterility (CMS) lines was elucidated by comparing the polymorphic sites in nine highly variable regions. A total of 151 polymorphic bases were detected among 29 materials; of which 131 bases were identified withindica-japonica characteristics. 17 CMS lines were divided into 3 cytoplasmic types: CMS-WA (wild-abortive), CMS-HL (Honglian) and CMS-BT (Boro II). CMS-WA contained V20A, Jin23A, GuangyeA, Chuangxiang29A, Zhenshan97A, T98A, Yong 6A, II 32A, ZhongjiuA, You1A, K17A, CIRAD496A and Gang46A; CMS-HL consisted of YuetaiA; CMS-BT contained T1A, 6A and 199A. All these three CMS types could be distinguished using these sequences: CMS-WA lines uniquely had a “GTTGAG” sequence at the position 220 to 225 of rps16 intron; CMS-HL lines contained a specific “G” base at position 595 of rps16 intron; and CMS-BT lines were also distinguishable by using their indica specific sequences “GCTT” inccsA gene under a japonica cpDNA background. On the other hand, it was proved that some genetic variations occurred in cpDNA of CMS, so, the cytoplasm resources of CMS lines were not ordinary, but some variants. However, further study is needed to reveal the relationship between these variations and pollen sterility.

Key words: Genetic diversity; cytoplasmic male sterility; chloroplast DNA; indica-japonica differentiation.