Quantitative trait loci (QTLs) and HQTL (heterosis QTLs) for grain shape are two major genetic factors of grain yield and quality in rice (Oryza sativa L.). Although many QTLs for grain shape have been reported, only a few are applied in production. In this study, 54 QTLs for grain shape were detected on 10 chromosomes using 33 SSSLs (single-segment substitution lines) and methods of statistical genetics. Among these, 23 exhibited significant positive additive genetic effects, including some novel QTLs, among which qTGW4-(1,2), qTGW10-2, and qTGW10-3 were three QTLs newly found in this study and should be paid more attention. Moreover, 26 HQTLs for grain shape were probed. Eighteen of these exhibited significant positive dominant genetic effects. Thirty-three QTLs for grain shape were further mapped using linkage analysis. Most of the QTLs for grain shape produced pleiotropic effects, which simultaneously controlled multiple appearance traits of grain shape. Linkage mapping of the F2 population derived from sub-single-segment substitution lines further narrowed the interval harbouring qTGW10-3 to 75.124 kb between PSM169 and RM25753. The candidate gene was identified and could be applied to breeding applications by molecular marker-assisted selection. These identified QTLs for grain shape will offer additional insights for improving grain yield and quality in rice breeding.

中文翻译：

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使用单段代换系对水稻（Oryza sativa L.）的粒形数量性状位点进行鉴定、精细定位和应用。

粒形数量性状位点 (QTL) 和 HQTL (杂种优势 QTL) 是水稻 (Oryza sativa L.) 籽粒产量和品质的两个主要遗传因子。尽管已经报道了许多关于粒形的QTL，但只有少数用于生产。在这项研究中，使用 33 个 SSSL（单段替换系）和统计遗传学方法在 10 条染色体上检测到 54 个粒形 QTL。其中，23个表现出显着的正加性遗传效应，包括一些新的QTL，其中qTGW4-(1,2)、qTGW10-2和qTGW10-3是本研究新发现的3个QTL，值得关注。此外，还检测了 26 个与晶粒形状有关的 HQTL。其中 18 个表现出显着的正显性遗传效应。使用连锁分析进一步定位了 33 个粒形 QTL。大多数粒形QTLs具有多效性，同时控制多个粒形外观性状。来自亚单段替代品系的 F2 种群的连锁作图进一步将包含 qTGW10-3 的区间缩小到 PSM169 和 RM25753 之间的 75.124 kb。候选基因被鉴定出来，可以通过分子标记辅助选择应用于育种应用。这些鉴定出的籽粒形状 QTL 将为水稻育种提高籽粒产量和品质提供更多见解。候选基因被鉴定出来，可以通过分子标记辅助选择应用于育种应用。这些鉴定出的籽粒形状 QTL 将为水稻育种提高籽粒产量和品质提供更多见解。候选基因被鉴定出来，可以通过分子标记辅助选择应用于育种应用。这些鉴定出的籽粒形状 QTL 将为水稻育种提高籽粒产量和品质提供更多见解。