BACKGROUND Continuous storage root formation and bulking (CSRFAB) in sweetpotato is an important trait from agronomic and biological perspectives. Information about the molecular mechanisms underlying CSRFAB traits is lacking. RESULTS Here, as a first step toward understanding the genetic basis of CSRFAB in sweetpotato, we performed a genome-wide association study (GWAS) using phenotypic data from four distinct developmental stages and 33,068 single nucleotide polymorphism (SNP) and insertion-deletion (indel) markers. Based on Bonferroni threshold (p-value < 5 × 10- 7), we identified 34 unique SNPs that were significantly associated with the complex trait of CSRFAB at 150 days after planting (DAP) and seven unique SNPs associated with discontinuous storage root formation and bulking (DCSRFAB) at 90 DAP. Importantly, most of the loci associated with these identified SNPs were located within genomic regions (using Ipomoea trifida reference genome) previously reported for quantitative trait loci (QTL) controlling similar traits. Based on these trait-associated SNPs, 12 and seven candidate genes were respectively annotated for CSRFAB and DCSRFAB traits. Congruent with the contrasting and inverse relationship between discontinuous and continuous storage root formation and bulking, a DCSRFAB-associated candidate gene regulates redox signaling, involved in auxin-mediated lateral root formation, while CSRFAB is enriched for genes controlling growth and senescence. CONCLUSION Candidate genes identified in this study have potential roles in cell wall remodeling, plant growth, senescence, stress, root development and redox signaling. These findings provide valuable insights into understanding the functional networks to develop strategies for sweetpotato yield improvement. The markers as well as candidate genes identified in this pioneering research for CSRFAB provide important genomic resources for sweetpotato and other root crops.

中文翻译：

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全基因组关联研究确定了控制六倍体甘薯连续贮藏根形成和膨胀的候选基因。

背景技术从农艺和生物学角度来看，甘薯的连续贮藏根形成和膨胀（CSRFAB）是一个重要的性状。缺乏有关 CSRFAB 性状背后的分子机制的信息。结果在这里，作为了解甘薯 CSRFAB 遗传基础的第一步，我们使用来自四个不同发育阶段的表型数据和 33,068 个单核苷酸多态性 (SNP) 和插入删除 (indel) 进行了全基因组关联研究 (GWAS) ) 标记。基于 Bonferroni 阈值（p 值 < 5 × 10- 7），我们鉴定了 34 个独特的 SNP，这些 SNP 与种植后 150 天 (DAP) 时 CSRFAB 的复杂性状显着相关，以及 7 个与不连续贮藏根形成和90 DAP 时的膨松度 (DCSRFAB)。重要的是，与这些已识别的 SNP 相关的大多数基因座都位于先前报道的控制相似性状的数量性状基因座 (QTL) 的基因组区域（使用三裂叶薯参考基因组）。基于这些性状相关的SNP，分别注释了12个和7个候选基因作为CSRFAB和DCSRFAB性状。与不连续和连续贮藏根形成和膨胀之间的对比和逆关系一致，DCSRFAB相关候选基因调节氧化还原信号，参与生长素介导的侧根形成，而CSRFAB富含控制生长和衰老的基因。结论 本研究中鉴定的候选基因在细胞壁重塑、植物生长、衰老、应激、根发育和氧化还原信号传导中具有潜在作用。这些发现为了解功能网络以制定提高甘薯产量的策略提供了宝贵的见解。CSRFAB 的这项开创性研究中确定的标记和候选基因为甘薯和其他块根作物提供了重要的基因组资源。