International Rice Research Institute, DAPO BOX 7777, Metro Manila, Philippines.
International Maize and Wheat Improvement Center (CIMMYT), Mexico, Mexico.
Sci Rep. 2018 Jan 26;8(1):1626. doi: 10.1038/s41598-018-20116-7.
To improve the grain yield of the lowland-adapted popular rice variety Samba Mahsuri under reproductive-stage drought (RS) and to understand the interactions between drought QTLs, two mapping populations were developed using marker-assisted selection (MAS) and marker-assisted recurrent selection (MARS). The mean grain yield of pyramided lines (PLs) with qDTY + qDTY in MAS is significantly higher under RS and irrigated control than lines with single QTLs. Among MARS PLs, lines with four qDTYs (qDTY + qDTY + qDTY + qDTY ) and two QTLs (qDTY + qDTY ) yielded higher than PLs with other qDTY combinations. The selected PLs showed a yield advantage of 0.3-2.0 t ha under RS. An allelic profile of MAS PLs having same qDTY combination but with different yields under drought was studied. Hierarchical clustering grouped together the selected lines with high yield under drought. Epistasis test showed the interaction of qDTY and qDTY loci with qDTY significantly increased yield under drought and all the lines with higher yield under drought possessed the conserved region of qDTY on chromosome 7. The positive interactions among QTLs, effectiveness of QTLs in different backgrounds, introgression of DTY QTLs together with resistance to biotic stresses shall help enhance grain yield under RS.
为提高适应低地的流行水稻品种 Samba Mahsuri 在生殖期干旱（RS）下的粒产量，并了解干旱 QTL 之间的相互作用，利用标记辅助选择（MAS）和标记辅助轮回选择（MARS）开发了两个作图群体。在 RS 和灌溉对照下，具有 qDTY + qDTY 的基因聚合系（PL）的平均粒产量显著高于具有单个 QTL 的 PL。在 MARS PL 中，具有四个 qDTYs（qDTY + qDTY + qDTY + qDTY ）和两个 QTLs（qDTY + qDTY ）的 PL 产量高于具有其他 qDTY 组合的 PL。选择的 PL 在 RS 下的产量优势为 0.3-2.0 t ha。研究了具有相同 qDTY 组合但在干旱下产量不同的 MAS PL 的等位基因谱。层次聚类将在干旱下具有高产的选择系聚在一起。上位性测验表明，qDTY 和 qDTY 位点与 qDTY 的互作在干旱下显著增加了产量，所有在干旱下具有更高产量的系都具有染色体 7 上 qDTY 的保守区域。QTL 之间的积极相互作用、QTL 在不同背景下的有效性、DTY QTL 的导入以及对生物胁迫的抗性将有助于提高 RS 下的粒产量。
