Seedling vigor is a desirable trait in direct-seeded rice (Oryza sativa L.) to improve plant establishment and enhance weed competition. In this study, a genome-wide association study (GWAS) on seedling vigor traits was performed on a rice panel of 244 accessions consisting of the five major rice subpopulations (aromatic, aus, tropical japonica, temperate japonica, and indica) using the 7K SNP Cornell-IR LD Rice Array. A total of seven seedling vigor-related traits were evaluated under controlled conditions in a growth chamber. All traits had a normal distribution with a wide range of phenotypic variation with CV between 27.6 and 43.9%, except for seedling dry weight, which had a CV of 11.4%. We identified 43 GWAS-quantitative trait locus (QTL) regions associated with different seedling vigor traits, of which 19 QTL regions were near previously identified genes or QTL regions. These findings confirmed 19 previous QTL and identified 24 potential novel QTL targets for marker-assisted breeding programs. Additionally, superior donors with high seedling vigor were identified and can be used for rice crop improvement in direct-seeded systems.

中文翻译：

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水稻幼苗活力相关性状的全基因组关联研究

幼苗活力是直播水稻 ( Oryza sativa L. )的理想性状，可改善植株定植和增强杂草竞争。在这项研究中，一项关于幼苗活力性状的全基因组关联研究 (GWAS) 在由 244 个水稻品种组成的水稻面板上进行，该面板由五个主要水稻亚群（芳香、aus、热带粳稻、温带粳稻和籼稻）组成。) 使用 7K SNP Cornell-IR LD Rice Array。在生长室中的受控条件下评估了总共七个幼苗活力相关性状。除幼苗干重的变异系数为 11.4% 外，所有性状均呈正态分布，表型变异范围较广，变异系数在 27.6% 至 43.9% 之间。我们确定了 43 个与不同幼苗活力性状相关的 GWAS 定量性状位点 (QTL) 区域，其中 19 个 QTL 区域靠近先前确定的基因或 QTL 区域。这些发现证实了 19 个先前的 QTL，并为标记辅助育种计划确定了 24 个潜在的新 QTL 目标。此外，还鉴定了具有高幼苗活力的优良供体，可用于直接播种系统中的水稻作物改良。