8月12日，《PNAS》杂志在线发表了由中国水稻研究所、深圳华大基因研究院和中国科学院遗传与发育研究所等单位合作的最新科研成果。这篇题为“Dissecting yield-associated loci in super hybrid rice by resequencing recombinant inbred lines and improving parental genome sequences”的论文，为超级杂交稻产量相关位点的解析提供了宝贵的材料和有效的途径。

中国的杂交稻为世界粮食生产作出了巨大贡献，作为超级杂交稻标杆组合的两优培九以其丰产特性，在生产上大面积种植。研究人员通过长期努力，构建出132个超级杂交稻两优培九的核心重组自交系和1709个用于基因克隆的大规模重组自交系，并进一步对核心重组自交系进行了基因组重测序，成功构建了超高分辨率的遗传连锁图谱。

基于高密度物理图谱，研究人员不仅更新了两优培九的父本品种93-11和新组装的母本品种培矮64s的基因组序列，还检测到43个与水稻产量密切相关的数量性状位点（QTL），其中包括20个尚未报道的新QTL。同时，利用大规模重组自交系群体，结合亲本基因组间大量精确的单核苷酸多态标记和插入缺失标记对两个QTL——qSN8和qSPB1加以精细定位，分别确定DTH8和LAX1为候选基因，其中qSN8通过互补实验证实为DTH8基因。该项研究还为进一步阐明超级稻产量的遗传基础以及分子育种应用搭建了理想平台。

论文摘要：

The growing world population and shrinkage of arable land demand yield improvement of rice, one of the most important staple crops. To elucidate the genetic basis of yield and uncover its associated loci in rice, we resequenced the core recombinant inbred lines of Liang-You-Pei-Jiu, the widely cultivated super hybrid rice, and constructed a high-resolution linkage map. We detected 43 yield-associated quantitative trait loci, of which 20 are unique. Based on the high-density physical map, the genome sequences of paternal variety 93-11 and maternal cultivar PA64s of Liang-You-Pei-Jiu were significantly improved. The large recombinant inbred line population combined with plentiful high-quality single nucleotide polymorphisms and insertions/deletions between parental genomes allowed us to fine-map two quantitative trait loci, qSN8 and qSPB1, and to identify days to heading8 and lax panicle1 as candidate genes, respectively. The quantitative trait locus qSN8 was further confirmed to be days to heading8 by a complementation test. Our study provided an ideal platform for molecular breeding by targeting and dissecting yield-associated loci in rice.

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