Submergence stress due to flash floods reduces rice yield drastically in sensitive varieties. Maudamani is a high yielding popular rice variety but is highly susceptible to submergence stress. The selection of progenies carrying Sub1 and GW5 (wide-grain) enhanced the submergence stress tolerance and grain yield of theMaudamani variety by following the marker-assisted backcross breeding method. Foreground screening detected 14 BC1F1, 17 BC2F1, and 12 BC3F1 backcross progenies that carried the target QTLs for submergence tolerance and grain width. Background screening was performed in the progenies carrying the target QTL and enhanced the recovery of a recipient parent’s genome by upto 96.875% in the BC3 pyramided line. The BC3F1 plant containing the highest recipient parent genome content and the target QTLs was self-pollinated. In BC3F2 generation, the target QTLs the Sub1 and GW5 (wide-grain) alleles and recipient parent’s yield component QTL OsSPL14 were tracked for homozygous states in the progenies. Seven pyramided lines showed tolerance to submergence for 14 days and higher grain yield than both the parents. The pyramided lines were similar to the recipient parent for the majority of the studied morphological and quality traits. The pyramided lines are useful as cultivars and can serve as potential donors for transfer of Sub1, OsSPL14, Gn1a, GW5 (wide-grain), and SCM2 QTLs.

中文翻译：

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标记辅助回交育种提高流行水稻品种 'Maudamani' 的耐淹性和谷物产量

山洪暴发造成的淹没压力会大大降低敏感品种的水稻产量。Maudamani 是一种高产的流行水稻品种，但极易受到淹没压力的影响。选择携带 Sub1 和 GW5（宽粒）的后代通过遵循标记辅助回交育种方法提高了 Maudamani 品种的淹没胁迫耐受性和谷物产量。前景筛选检测到 14 个 BC1F1、17 个 BC2F1 和 12 个 BC3F1 回交后代，这些后代携带了耐淹性和粒宽的目标 QTL。背景筛选在携带目标 QTL 的后代中进行，并在 BC3 金字塔线中将受体亲本基因组的回收率提高了 96.875%。含有最高受体亲本基因组含量和目标 QTL 的 BC3F1 植物是自花授粉的。在 BC3F2 代中，跟踪目标 QTL、Sub1 和 GW5（宽粒）等位基因和受体亲本的产量分量 QTL OsSPL14 以寻找后代中的纯合状态。七个金字塔形品系显示出对浸水的耐受性 14 天，并且比两个亲本都具有更高的谷物产量。对于大多数研究的形态和质量特征，金字塔线与受体亲本相似。金字塔线可用作栽培品种，并可作为 Sub1、OsSPL14、Gn1a、GW5（宽粒）和 SCM2 QTL 转移的潜在供体。对于大多数研究的形态和质量特征，金字塔线与受体亲本相似。金字塔线可用作栽培品种，并可作为 Sub1、OsSPL14、Gn1a、GW5（宽粒）和 SCM2 QTL 转移的潜在供体。对于大多数研究的形态和质量特征，金字塔线与受体亲本相似。金字塔线可用作栽培品种，并可作为 Sub1、OsSPL14、Gn1a、GW5（宽粒）和 SCM2 QTL 转移的潜在供体。