Berdugo-Cely Jhon A, Céron-Lasso María Del Socorro, Yockteng Roxana
Corporación Colombiana de Investigación Agropecuaria-AGROSAVIA, Centro de Investigación Turipaná, Km 13 vía Montería-Cereté, Montería, Córdoba, Colombia.
Corporación Colombiana de Investigación Agropecuaria (AGROSAVIA), Centro de Investigación Tibaitatá, Km 13 vía Mosquera-Bogotá, Mosquera, Cundinamarca, Colombia.
Front Plant Sci. 2023 Jan 18;13:1007104. doi: 10.3389/fpls.2022.1007104. eCollection 2022.
Potato tubers contain biochemical compounds with antioxidant properties that benefit human health. However, the genomic basis of the production of antioxidant compounds in potatoes has largely remained unexplored. Therefore, we report the first genome-wide association study (GWAS) based on 4488 single nucleotide polymorphism (SNP) markers and the phenotypic evaluation of Total Phenols Content (TPC), Ascorbic Acid Content (AAC), and Antioxidant Activity (AA) traits in 404 diverse potato genotypes (84 diploids and 320 tetraploids) conserved at the Colombian germplasm bank that administers AGROSAVIA. The concentration of antioxidant compounds correlated to the skin tuber color and ploidy level. Especially, purple-blackish tetraploid tubers had the highest TPC (2062.41 ± 547.37 mg GAE), while diploid pink-red tubers presented the highest AA (DDPH: 14967.1 ± 4687.79 μmol TE; FRAP: 2208.63 ± 797.35 mg AAE) and AAC (4.52 mg ± 0.68 AA). The index selection allowed us to choose 20 promising genotypes with the highest values for the antioxidant compounds. Genome Association mapping identified 58 SNP-Trait Associations (STAs) with single-locus models and 28 Quantitative Trait Nucleotide (QTNs) with multi-locus models associated with the evaluated traits. Among models, eight STAs/QTNs related to TPC, AAC, and AA were detected in common, flanking seven candidate genes, from which four were pleiotropic. The combination in one population of diploid and tetraploid genotypes enabled the identification of more genetic associations. However, the GWAS analysis implemented independently in populations detected some regions in common between diploids and tetraploids not detected in the mixed population. Candidate genes have molecular functions involved in phenolic compounds, ascorbic acid biosynthesis, and antioxidant responses concerning plant abiotic stress. All candidate genes identified in this study can be used for further expression analysis validation and future implementation in marker-assisted selection pre-breeding platforms targeting fortified materials. Our study further revealed the importance of potato germplasm conserved in national genebanks, such as AGROSAVIA's, as a valuable genetic resource to improve existing potato varieties.
马铃薯块茎含有具有抗氧化特性的生化化合物，对人体健康有益。然而，马铃薯中抗氧化化合物产生的基因组基础在很大程度上仍未得到探索。因此，我们报告了第一项全基因组关联研究（GWAS），该研究基于4488个单核苷酸多态性（SNP）标记，并对保存在管理AGROSAVIA的哥伦比亚种质库中的404种不同马铃薯基因型（84个二倍体和320个四倍体）的总酚含量（TPC）、抗坏血酸含量（AAC）和抗氧化活性（AA）性状进行了表型评估。抗氧化化合物的浓度与块茎皮颜色和倍性水平相关。特别是，紫黑色四倍体块茎的TPC最高（2062.41±547.37毫克没食子酸当量），而二倍体粉红红色块茎的AA最高（DDPH：14967.1±4687.79微摩尔TE；FRAP：2208.63±797.35毫克AAE）和AAC最高（4.52毫克±0.68 AA）。指数选择使我们能够选择20种抗氧化化合物含量最高的有前景的基因型。基因组关联图谱鉴定出58个单基因座模型的SNP-性状关联（STA）和28个与评估性状相关的多基因座模型的数量性状核苷酸（QTN）。在这些模型中，共检测到8个与TPC、AAC和AA相关的STA/QTN，位于7个候选基因两侧，其中4个是多效性的。二倍体和四倍体基因型在一个群体中的组合使得能够鉴定出更多的遗传关联。然而，在群体中独立实施的GWAS分析检测到二倍体和四倍体之间一些在混合群体中未检测到的共同区域。候选基因具有参与酚类化合物、抗坏血酸生物合成以及与植物非生物胁迫相关的抗氧化反应的分子功能。本研究中鉴定的所有候选基因可用于进一步的表达分析验证以及未来在针对强化材料的标记辅助选择预育种平台中的应用。我们的研究进一步揭示了保存在国家基因库（如AGROSAVIA的基因库）中的马铃薯种质作为改善现有马铃薯品种的宝贵遗传资源的重要性。
