Okada Satoshi, Onogi Akio, Iijima Ken, Hori Kiyosumi, Iwata Hiroyoshi, Yokoyama Wakana, Suehiro Miki, Yamasaki Masanori
Food Resources Education and Research Center, Graduate School of Agricultural Science, Kobe University, Kasai, Hyogo 675-2103, Japan.
Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-Ku, Tokyo 113-8657, Japan.
Breed Sci. 2018 Mar;68(2):210-218. doi: 10.1270/jsbbs.17112. Epub 2017 Sep 6.
Grain size is important for brewing-rice cultivars, but the genetic basis for this trait is still unclear. This paper aims to identify QTLs for grain size using novel chromosomal segment substitution lines (CSSLs) harboring chromosomal segments from Yamadanishiki, an excellent sake-brewing rice, in the genetic background of Koshihikari, a cooking cultivar. We developed a set of 49 CSSLs. Grain length (GL), grain width (GWh), grain thickness (GT), 100-grain weight (GWt) and days to heading (DTH) were evaluated, and a CSSL-QTL analysis was conducted. Eighteen QTLs for grain size and DTH were identified. Seven (, , , , , , and ) that were detected in F and recombinant inbred lines (RILs) from Koshihikari/Yamadanishiki were validated, suggesting that they are important for large grain size and heading date in Yamadanishiki. Additionally, QTL reanalysis for GWt showed that was only detected in early-flowering RILs, while (in the same region as ) was only detected in late-flowering RILs, suggesting that these QTLs show different responses to the environment. Our study revealed that grain size in the Yamadanishiki cultivar is determined by a complex genetic mechanism. These findings could be useful for the breeding of both cooking and brewing rice.
粒型对酿造用稻品种很重要，但该性状的遗传基础仍不清楚。本文旨在利用一套新型染色体片段代换系（CSSL）来鉴定粒型的数量性状基因座（QTL），这些代换系在食用品种越光的遗传背景中含有优质酿酒水稻山田锦的染色体片段。我们构建了一套包含49个CSSL的群体。对粒长（GL）、粒宽（GWh）、粒厚（GT）、百粒重（GWt）和抽穗天数（DTH）进行了评估，并开展了CSSL-QTL分析。共鉴定出18个控制粒型和DTH的QTL。在越光/山田锦杂交F2和重组自交系（RIL）中检测到的7个QTL（、、、、、、）得到了验证，表明它们对山田锦的大粒型和抽穗期很重要。此外，对GWt的QTL重新分析表明，仅在早花RIL中检测到，而（与位于同一区域）仅在晚花RIL中检测到，这表明这些QTL对环境的响应不同。我们的研究表明，山田锦品种的粒型由复杂的遗传机制决定。这些发现可能对食用稻和酿酒稻的育种都有用。
