Background

Stigma exsertion rate (SER) is a key determinant for the outcrossing ability of male sterility lines (MSLs) in hybrid rice seed production. In the process of domestication, the outcrossing ability of cultivated rice varieties decreased, while that of wild Oryza species kept strong. Here, we detected the quantitative trait loci (QTLs) controlling SER using a set of single-segment substitution lines (SSSLs) derived from O. glumaepatula, a wild Oryza species.

Results

Seven QTLs for SER were located on 5 chromosomes. qSER-1a and qSER-1b were located on chromosome 1. qSER-3a and qSER-3b were mapped on chromosome 3, and qSER-3b was further located at an estimated interval of 898.8 kb by secondary substitution mapping. qSER-5, qSER-9 and qSER-10 were identified on chromosomes 5, 9 and 10, respectively, and qSER-9 was delimited to an estimated region of 551.9 kb by secondary substitution mapping. The additive effects of the 7 QTLs ranged from 10.6% to 14.8%, which were higher than those of most loci for SER reported previously.

Conclusions

qSER-1a and qSER-1b are novel loci for SER on chromosome 1. All of the 7 QTLs have major effects on SER. The major QTLs of SER will help to develop MSLs with strong outcrossing ability.

中文翻译：

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控制稻米柱头外露率的主要数量性状基因座的取代图。

背景

柱头外露率（SER）是杂交水稻种子生产中雄性不育系（MSL）异型能力的关键决定因素。在驯化过程中，栽培水稻品种的异交能力下降，而野生稻的异交能力保持强势。在这里，我们检测到的数量性状基因座（QTL）控制使用一组衍生自单段代换系（单片段代换系）的SER O. glumaepatula，野生稻品种。

结果

SER的七个QTL位于5条染色体上。qSER-1a和qSER-1b位于1号染色体上。qSER-3a和qSER-3b被定位在3号染色体上，而qSER-3b通过二次置换图谱位于估计的间隔为898.8 kb。qSER-5，qSER-9和qSER-10分别在5号，9号和10号染色体上鉴定，并且qSER-9通过二次置换图谱划分为551.9 kb的估计区域。这7个QTL的加性作用范围为10.6％至14.8％，高于先前报道的SER的大多数基因座。

结论

qSER-1a和qSER-1b是1号染色体上SER的新位点。所有7个QTL对SER都有重要影响。SER的主要QTL将有助于开发具有强大的异源杂交能力的MSL。