Salinity tolerance plays an important role in direct seeding cultivation since tolerance to salinity at the bud burst stage of rice directly affects seedling formation and yield. However, information on the quantitative trait loci (QTL) associated with salinity tolerance at the bud burst stage is limited. Here, a recombinant inbred line (RIL) population, derived from a cross between Kongyu131 (salinity-sensitive) and Xiaobaijingzi (salinity-tolerant), was used to identify QTLs for salinity tolerance at the bud burst stage using a high-density genetic map. Four QTLs were identified. The threshold LOD score for QTL identification was 3.0. Among the four QTLs detected, two QTLs namely qRSL3 (PVE, 22.59%) and qRRL3 (PVE, 21.21%) were considered to be one QTL, named qST3, which was the major QTL related to salinity tolerance on chromosome 3. This major QTL was located within an interval of 2.55 Mb and contained 253 candidate genes. Using RNA-seq data, 51 differentially expressed genes (DEGs) were detected among the candidate region. According to Rice Annotation Project and quantitative real-time PCR (qRT-PCR) analysis, Os03g0664800 was accepted as the most likely candidate gene for qST3. These results will be useful for improving salinity tolerance of rice and for developing rice cultivars suitable for direct seeding in salinized soil.

耐盐性在直播栽培中起着重要作用，因为水稻萌芽期耐盐性直接影响幼苗的形成和产量。然而，关于芽破阶段耐盐性相关的数量性状基因座（QTL）的信息是有限的。在这里，一个重组自交系 (RIL) 种群源自孔育 131（盐敏感）和小白井子（耐盐）之间的杂交，用于使用高密度遗传图谱鉴定芽破阶段耐盐的 QTL . 鉴定了四个QTL。QTL 鉴定的阈值 LOD 分数为 3.0。在检测到的4个QTL中，qRSL3（PVE，22.59%）和qRRL3（PVE，21.21%）2个QTL被认为是一个QTL，命名为qST3，是3号染色体耐盐性相关的主要QTL。该主要QTL位于2.55Mb区间内，包含253个候选基因。使用 RNA-seq 数据，在候选区域中检测到 51 个差异表达基因 (DEG)。根据水稻注释计划和实时定量 PCR (qRT-PCR) 分析，Os03g0664800被认为是最可能的qST3候选基因。这些结果将有助于提高水稻的耐盐性和开发适合在盐渍化土壤中直播的水稻品种。