Table_4_Construction of ddRADseq-Based High-Density Genetic Map and Identification of Quantitative Trait Loci for Trans-resveratrol Content in Peanut Seeds.XLSX

Resveratrol (trans-3,4′,5-trihydroxystilbene) is a natural stilbene phytoalexin which is also found to be good for human health. Cultivated peanut (Arachis hypogaea L.), a worldwide important legume crop, is one of the few sources of human's dietary intake of resveratrol. Although the variations of resveratrol contents among peanut varieties were observed, the variations across environments and its underlying genetic basis were poorly investigated. In this study, the resveratrol content in seeds of a recombination inbred line (RIL) population (Zhonghua 6 × Xuhua 13, 186 progenies) were quantified by high performance liquid chromatography (HPLC) method across four environments. Genotypes, environments and genotype × environment interactions significantly influenced the resveratrol contents in the RIL population. A total of 8,114 high-quality single nucleotide polymorphisms (SNPs) were identified based on double-digest restriction-site-associated DNA sequencing (ddRADseq) reads. These SNPs were clustered into bins using a reference-based method, which facilitated the construction of high-density genetic map (2,183 loci with a total length of 2,063.55 cM) and the discovery of several chromosome translocations. Through composite interval mapping (CIM), nine additive quantitative trait loci (QTL) for resveratrol contents were identified on chromosomes A01, A07, A08, B04, B05, B06, B07, and B10 with 5.07–8.19% phenotypic variations explained (PVE). Putative genes within their confidential intervals might play roles in diverse primary and secondary metabolic processes. These results laid a foundation for the further genetic dissection of resveratrol content as well as the breeding and production of high-resveratrol peanuts.

白藜芦醇（Resveratrol，反式-3,4′,5-三羟基芪）是一种天然芪类植物抗毒素，同时被发现对人体健康有益。栽培花生（Arachis hypogaea L.）作为全球重要的豆科作物，是人类膳食中白藜芦醇的少数几种来源之一。尽管已有研究观察到不同花生品种间的白藜芦醇含量存在差异，但针对环境间的含量变异及其潜在遗传基础的研究仍较为匮乏。本研究通过高效液相色谱法（high performance liquid chromatography, HPLC），在4种环境下对重组自交系（recombination inbred line, RIL）群体（中花6号×徐花13号，包含186个家系）的种子白藜芦醇含量进行了定量检测。该群体的白藜芦醇含量显著受基因型、环境以及基因型×环境互作的影响。基于双酶切限制性位点相关DNA测序（double-digest restriction-site-associated DNA sequencing, ddRADseq）的读段数据，本研究共鉴定得到8114个高质量单核苷酸多态性（single nucleotide polymorphisms, SNPs）。通过参考基因组辅助的方法将这些SNPs聚类为bin标记，进而构建了高密度遗传图谱（包含2183个位点，总长度为2063.55 cM），并发现了若干染色体易位事件。通过复合区间作图法（composite interval mapping, CIM），本研究在A01、A07、A08、B04、B05、B06、B07及B10染色体上共鉴定得到9个控制白藜芦醇含量的加性数量性状基因座（quantitative trait loci, QTL），其表型解释率（phenotypic variations explained, PVE）为5.07%~8.19%。位于这些QTL置信区间内的候选基因可能参与多种初级和次级代谢过程。本研究结果为后续白藜芦醇含量的遗传解析以及高白藜芦醇含量花生的育种与生产奠定了基础。