College of Life Sciences, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
J Integr Plant Biol. 2013 Jun;55(6):504-13. doi: 10.1111/jipb.12048. Epub 2013 May 15.
A salt-sensitive mutant designated rice salt sensitive 2 (rss2) was isolated from the M2 generation of the rice cultivar Nipponbare mutagenized with ethyl methanesulfonate (EMS). This mutant exhibited a greater decrease in salt tolerance with a significant increase in Na(+) content in its shoots. Genetic analysis indicated that the increase in Na(+) in rss2 was controlled by a single recessive gene. Further genome-wide analysis of the linkage map constructed from the F2 population of rss2/Zhaiyeqing 8 (ZYQ8) showed that two quantitative trait loci (QTLs) on chromosomes 1 and 6 were responsible for the Na(+) concentration in shoots, which explained 14.5% and 53.3%, respectively, of the phenotypic variance. The locus on chromosome 1, but not that on chromosome 6, was also detected in the F2 population of Nipponbare/ZYQ8, suggesting that the QTL on chromosome 6 was responsible for the salt sensitivity in rss2. By analyzing the recombination events in 220 mutant individuals of an enlarged mapping population of rss2/ZYQ8, the rss2 locus was precisely mapped to an interval of 605.3 kb between insertion/deletion (InDel) markers IM21962 and IM22567. This finding will facilitate the cloning of the rss2 locus and provide insight into the physiological mechanisms of salt sensitivity in rice.
从经乙基甲磺酸（EMS）诱变的水稻品种‘Nipponbare’的 M2 代中分离到一个盐敏感突变体，命名为水稻盐敏感 2（rss2）。该突变体表现出对盐胁迫的敏感性降低， shoots 中的 Na+含量显著增加。遗传分析表明，rss2 中 Na+的增加受单个隐性基因控制。进一步对 rss2/Zhaiyeqing 8（ZYQ8）F2 群体构建的连锁图谱进行全基因组分析表明，第 1 和第 6 染色体上的两个数量性状位点（QTL）负责 shoots 中的 Na+浓度，分别解释了表型方差的 14.5%和 53.3%。第 1 染色体上的位点，但不是第 6 染色体上的位点，也在 Nipponbare/ZYQ8 的 F2 群体中被检测到，表明第 6 染色体上的 QTL 是 rss2 盐敏感性的原因。通过分析 rss2/ZYQ8 扩大作图群体中 220 个突变个体的重组事件，将 rss2 基因精确定位在插入/缺失（InDel）标记 IM21962 和 IM22567 之间的 605.3kb 区间内。这一发现将有助于 rss2 基因座的克隆，并为水稻盐敏感性的生理机制提供深入了解。
