Abstract: A rice floral mutant with twin-ovary and dwarf plant was isolated from the progenies of the combination of C2/Mianxiang 5B.By anatomical observations,the mutant was characterized with the phenotypes of fewer stamens,more pistils and stigmas,twin-ovary,malformed embryo sac,as well as stamen-originated pistils.Due to its exceeding sterility,the mutation was maintained by heterozygotes,and it was also inherited stably after five generations of self-pollination.The segregation ratio of wild type plants to mutant plants in the population degenerated from heterozygotes was 3∶1,indicating that the mutant is controlled by a single recessive gene,and designated tentatively as TOR.

Key words: rice, twin-ovary mutant, floral organ, genetic analysis, gene

摘要： 在籼稻保持系C2与绵香5B的杂交后代中发现了一个植株显著矮化的双子房突变体。该突变体花器官主要表现为：雄蕊数目减少,雌蕊增加，双子房，多柱头，胚囊畸形，有雄蕊雌蕊化现象。由于其高度不育，突变性状采用杂合体保存，经5代连续自交，均表现稳定遗传特性。同时，杂合株系呈典型的3∶1分离比例，表明该突变性状由单隐性基因控制，并将该突变体暂时命名为TOR。

关键词: 水稻, 双子房突变体, 花器官, 遗传分析, 基因