【摘要】 【目的】盐胁迫是制约水稻生产的主要环境胁迫之一，研究耐盐水稻品种响应盐胁迫的生理特征，分析耐盐基因等位变异及表达，为耐盐水稻品种选育提供重要的基因资源和遗传材料。【方法】首先对南粳系列优质水稻品种（系）的苗期耐盐性进行鉴定，以盐处理条件下的存活率作为指标，筛选耐盐性强的品种。分析其在盐胁迫下的生理指标变化，包括叶绿素、Na⁺、K⁺、MDA、H₂O₂、可溶性糖等含量。通过基因组测序解析强耐盐性品种中耐盐基因的变异类型，以及通过检测耐盐基因的表达水平，解析强耐盐品种响应盐胁迫的分子机制。【结果】在140 mmol·L^-1 NaCl处理6 d条件下，南粳9108、南粳5718、南粳盐1号的存活率大于60%，在供试品种中的存活率最高；与对照品种日本晴相比，盐胁迫下，南粳9108、南粳5718、南粳盐1号幼苗含有较高的叶绿素含量、较低的MDA含量，表明盐胁迫对这3个品种造成的细胞损伤较低；南粳9108、南粳5718和南粳盐1号的根系Na⁺/K⁺明显高于日本晴，而地上部Na⁺/K⁺明显低于日本晴，表明这3个耐盐品种根系吸收或者储存的Na⁺较多，但向上运输的Na⁺少，有利于维持细胞离子平衡，对地上部造成的离子毒害和渗透胁迫影响较小；这3个耐盐品种有23个耐盐基因存在94个SNP或InDel位点，分布于外显子、内含子、5′UTR和3′UTR,11个基因的24个变异位点发生在外显子上，其中，有7个基因发生移码突变或错义突变，分布于Os02g0813500（OsGR2）、Os05g0343400（OsWRKY53）、Os06g0685700（OsRST1）、Os07g0685700（OsEIL2）、Os10g0431000（OsPQT3）、Os11g0446000（OsRSS3）、Os12g0150200（P450）；盐胁迫显著诱导耐盐品种中耐盐基因OsSKC1、OsBAG4、OsGPX1、OsCCX2、OsGR3、OsDREB2a、OsRAB21、OsP5CS、OsbZIP23、OsAPX37、OsLEA3等的表达，可增强水稻对盐胁迫的耐受性，减少盐害对水稻生长的不利影响。【结论】南粳9108、南粳5718和南粳盐1号3个品种具有较强的苗期耐盐性，这与盐胁迫下的钠钾离子平衡、多个耐盐基因的等位变异、基因表达水平等密切相关。南粳9108、南粳5718和南粳盐1号聚合了多个耐盐优质基因，可作为耐盐品种选育的骨干亲本进行遗传改良和育种应用研究。更多还原

【Abstract】 【Objective】Salt stress is one of the main environmental stresses that restrict rice production. Studying the physiological characteristics under salt stress and analysis the allelic variation and expression of salt-tolerance genes provide key gene resources and genetic materials for breeding salt-tolerance rice varieties. 【Method】This study first evaluated the salt-tolerance ability of the Nangeng series high-quality rice varieties/lines during the seedling stage, using survival rate as an indicator for screening salt-tolerance varieties, which physiological changes under salt stress were analyzed, including chlorophyll, Na⁺, K⁺, MDA, H₂O₂ and soluble sugar. The variation types and expression levels of salt-tolerance genes in rice varieties with resistance to high salt concentration were also analyzed to explaining their molecular mechanisms in response to salt stress. 【Result】Under the condition of treating with 140 mmol·L^-1 NaCl for 6 days, the survival rates of NG9108, NG5718, and NGY1 were greater than 60%, with the highest survival rate among the tested varieties. Compared with Nipponbare, the seedlings of NG9108, NG5718, and NGY1 under salt stress had higher chlorophyll content and lower MDA content, indicating that salt stress caused less cell damage to the three varieties. The Na⁺/K⁺ values in the roots of NG9108, NG5718, and NGY1 were significantly higher than those in Nipponbare, while the Na⁺/K⁺ values in the aerial parts were significantly lower than those in Nipponbare, implying that the three varieties absorb or store more Na⁺ in roots, but transport less Na⁺ upwards, which is beneficial for maintaining cell ion balance and causing less ion toxicity and osmotic stress in aerial parts of the seedlings. The three salt-tolerance varieties have 94 SNPs or InDel sites, distributing in exons, introns, 5′UTR, and 3′UTR of the 23 salt-tolerance genes. 24 variation sites of 11 genes occur in the exons, including 7 genes with frameshift mutations or missense mutations which distributed in Os02g0813500（OsGR2）, Os05g0343400（OsWRKY53）, Os06g0685700（OsRST1）, Os07g0685700（OsEIL2）, Os10g0431000（OsPQT3）, Os11g044600（OsRSS3）, Os12g0150200（P450）. Salt stress significantly induces expression of OsSKC1, OsBAG4, OsGPX1, OsCCX2, OsGR3, OsDREB2a, OsRAB21, OsP5CS, OsbZIP23, OsAPX37 and OsLEA3, which help to enhance salt tolerance and reduce the adverse effects of salt damage on rice growth. 【Conclusion】NG9108, NG5718 and NGY1 showed strong salt tolerance phenotype during the seedling growth stage, which is closely related to the balance of sodium and potassium ions under salt stress, allelic variations of multiple salt tolerance genes, and gene expression levels. NG9108, NG5718 and NGY1 have pyramided multiple salt tolerant and high-quality genes, which can be used as backbone parents for genetic improvement and breeding.更多还原