Guangdong Key Lab of Plant Molecular Breeding, South China Agricultural University, Guangzhou, 510642, People's Republic of China.
Theor Appl Genet. 2012 Jun;125(1):143-53. doi: 10.1007/s00122-012-1822-x. Epub 2012 Feb 21.
Twelve single segment substitution lines (SSSLs) in rice, which contain quantitative trait loci (QTLs) for tiller number detected previously, were used to study dynamic expression of the QTLs in this study. These SSSLs and their recipient, Hua-Jing-Xian 74 (HJX74), were used to produce 78 crossing combinations first, and then these combinations and their parents were grown in two planting seasons with three cropping densities. Tiller number was measured at seven developmental stages. QTL effects including main effects (additive, dominance and epistasis), QTL × season and QTL × density interaction effects were analyzed at each measured stage. The additive, dominant and epistatic effects of the 12 QTLs as well as their interaction effects with the seasons and with the densities all display dynamic changes with the development. Eight QTLs are detected with significant additive effects and/or additive × season and/or additive × density interaction effects at least at one developmental stage, and all QTLs have significant dominant and epistatic effects and/or interaction effects involved in. For most of the QTLs dominant effects are much bigger than additive effects, showing overdominance. Each QTL interacts at least with eight other QTLs. Additive and dominant effects of these QTLs are mostly positive while epistatic effects are negative and minor. Most of the QTLs show significant interactions with planting seasons and cropping densities, but the additive effects of QTLs Tn3-1 and Tn3-2, the dominant effects of QTL Tn7 and Tn8, and the epistatic effects of 14 pairs of QTLs are stable across seasons and the dominant effect of QTL Tn3-3 and the epistatic effects of QTL pairs Tn2-1/Tn6-2, Tn2-1/Tn9 and Tn3-3/Tn6-3 are nearly consistent across cropping densities. This paper is the first report of dynamics on dominances and epistasis of QTLs for tiller number in rice and provides abundant information, which is useful to improve rice tiller number via heterosis and/or QTL pyramiding.
利用包含先前检测到的分蘖数数量性状位点 (QTL) 的 12 个单片段替换系 (SSSL) 研究这些 QTL 的动态表达。这些 SSSL 及其受体华粳 74 (HJX74) 首先用于产生 78 个杂交组合，然后在两个种植季节和三种种植密度下种植这些组合及其亲本。在七个发育阶段测量分蘖数。在每个测量阶段分析 QTL 效应，包括主效应（加性、显性和上位性）、QTL×季节和 QTL×密度互作效应。12 个 QTL 的加性、显性和上位性效应及其与季节和密度的互作效应均随发育而动态变化。在至少一个发育阶段检测到 8 个 QTL 具有显著的加性效应和/或加性×季节和/或加性×密度互作效应，并且所有 QTL 均具有显著的显性和上位性效应以及涉及的互作效应。对于大多数 QTL，显性效应远大于加性效应，表现出超显性。每个 QTL 至少与其他 8 个 QTL 相互作用。这些 QTL 的加性和显性效应主要为正，而上位性效应为负且较小。大多数 QTL 与种植季节和种植密度存在显著互作，但 QTL Tn3-1 和 Tn3-2 的加性效应、QTL Tn7 和 Tn8 的显性效应以及 14 对 QTL 的上位性效应在季节间稳定，而 QTL Tn3-3 的显性效应和 QTL 对 Tn2-1/Tn6-2、Tn2-1/Tn9 和 Tn3-3/Tn6-3 的上位性效应在种植密度间几乎一致。本文首次报道了水稻分蘖数 QTL 的显性和上位性的动态变化，提供了丰富的信息，有助于通过杂种优势和/或 QTL 聚合提高水稻分蘖数。
