Corteva Agriscience, Rio Verde, GO, Brazil.
Department of Agronomy, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
J Exp Bot. 2022 Sep 12;73(16):5460-5473. doi: 10.1093/jxb/erac236.
The identification of genomic regions associated with root traits and the genomic prediction of untested genotypes can increase the rate of genetic gain in maize breeding programs targeting roots traits. Here, we combined two maize association panels with different genetic backgrounds to identify single nucleotide polymorphisms (SNPs) associated with root traits, and used a genome-wide association study (GWAS) and to assess the potential of genomic prediction for these traits in maize. For this, we evaluated 377 lines from the Ames panel and 302 from the Backcrossed Germplasm Enhancement of Maize (BGEM) panel in a combined panel of 679 lines. The lines were genotyped with 232 460 SNPs, and four root traits were collected from 14-day-old seedlings. We identified 30 SNPs significantly associated with root traits in the combined panel, whereas only two and six SNPs were detected in the Ames and BGEM panels, respectively. Those 38 SNPs were in linkage disequilibrium with 35 candidate genes. In addition, we found higher prediction accuracy in the combined panel than in the Ames or BGEM panel. We conclude that combining association panels appears to be a useful strategy to identify candidate genes associated with root traits in maize and improve the efficiency of genomic prediction.
鉴定与根系性状相关的基因组区域和对未测试基因型进行基因组预测，可以提高以根系性状为目标的玉米育种计划的遗传增益速度。在这里，我们将两个具有不同遗传背景的玉米关联群体进行了组合，以鉴定与根系性状相关的单核苷酸多态性（SNP），并使用全基因组关联研究（GWAS）来评估这些性状在玉米中的基因组预测潜力。为此，我们评估了来自 Ames 群体的 377 个系和来自 Backcrossed Germplasm Enhancement of Maize（BGEM）群体的 302 个系，在一个由 679 个系组成的综合群体中进行了评估。这些系用 232460 个 SNP 进行了基因型分析，从 14 天龄的幼苗中收集了四个根系性状。我们在综合群体中鉴定出 30 个与根系性状显著相关的 SNP，而在 Ames 和 BGEM 群体中分别仅检测到 2 个和 6 个 SNP。这些 38 个 SNP 与 35 个候选基因存在连锁不平衡。此外，我们发现综合群体中的预测准确性高于 Ames 或 BGEM 群体。我们得出结论，组合关联群体似乎是一种有用的策略，可以鉴定与玉米根系性状相关的候选基因，并提高基因组预测的效率。
