Transmission ratio distortion (TRD) refers to a widespread phenomenon in which one allele is transmitted by heterozygotes more frequently to the progeny than the opposite allele. TRD is considered as a mark suggesting the presence of a reproductive barrier. However, the genetic and molecular mechanisms underlying TRD in rice remain largely unknown. In the present study, a population of backcross inbred lines (BILs) derived from the cross of a japonica cultivar Nipponbare (NIP) and an indica variety 9311 was utilized to study the genetic base of TRD. A total of 18 genomic regions were identified for TRD in the BILs. Among them, 12 and 6 regions showed indica (9311) and japonica (NIP) alleles with preferential transmission, respectively. A series of F₂ populations were used to confirm the TRD effects, including six genomic regions that were confirmed by chromosome segment substitution line (CSSL)-derived F₂ populations from intersubspecific allelic combinations. However, none of the regions was confirmed by the CSSL-derived populations from intrasubspecific allelic combination. Furthermore, significant epistatic interaction was found between TRD1.3 and TRD8.1 suggesting that TRD could positively contribute to breaking intersubspecific reproductive barriers. Our results have laid the foundation for identifying the TRD genes and provide an effective strategy to breakdown TRD for breeding wide-compatible lines, which will be further utilized in the intersubspecific hybrid breeding programs.

传递比畸变（TRD）是指一种普遍的现象，其中一个等位基因比异等位基因更频繁地被杂合子传递给后代。TRD被认为是表明存在生殖屏障的标记。但是，水稻中TRD的遗传和分子机制仍然未知。在本研究中，回交自交系（BIL）的种群来源于粳稻 品种Nipponbare（NIP）和 印度利用9311品种研究TRD的遗传基础。在BIL中共鉴定出TRD的18个基因组区域。其中，有12和6个区域显示印度 （9311）和 粳稻（NIP）等位基因分别具有优先传播。使用一系列F ₂种群来确认TRD效应，包括六个基因组区域，这些区域已通过染色体片段替换系（CSSL）衍生自亚种间等位基因组合的F ₂种群进行了确认。但是，没有任何区域被亚种内等位基因组合的CSSL衍生种群确认。此外，发现之间显着的上位性相互作用TRD1.3 和 TRD8.1提示TRD可能对打破亚种间生殖障碍起到积极作用。我们的结果为鉴定TRD基因奠定了基础，并提供了一种有效的策略来分解TRD，以培育广泛兼容的品系，并将进一步用于亚种间杂种育种计划。