ABSTRACT The colour of fresh pods is one of the most important traits that affects the commercial value of cowpea (Vigna unguiculata) beans. To investigate the genetic architecture, we firstly scored the fresh pod colour of cowpea for six generations in field trials. Afterwards, an F2 population of 150 recombinant individuals was derived from crosses between two high-generation inbred cowpea lines, ‘Baojia’ (green pod colour, P1) and ‘Qilong’ (purple pod colour, P2). Ahigh-density genetic map based on 9,493 single nucleotide polymorphisms was constructed through SLAF sequencing and used for gene/s mapping of pod colour trait. We observed 59 single nucleotide polymorphism markers in one candidate gene region that may be associated with fresh pod colour trait located on LG6. The locus of pc was confirmed on chromosome 5 of the cowpea genome, which was corresponded to the genes encoding anthocyanin 5-aromatic acyltransferase and MYB-90 and MYB-114 domain proteins, that play important roles in the anthocyanin biosynthesis. Lastly, dCAPS markers were developed that explained the high rate of identification for the phenotypes of the F2 population. This study provides new knowledge of the genomic regions and will accelerate the genetic improvements, regarding the fresh pod colour (pc) trait in cowpea and marker-assisted selection.

中文翻译：

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豇豆（Vigna unguiculata L. Walp.）基于SNP的高密度遗传图谱和豆荚颜色性状基因图谱的开发

摘要 新鲜豆荚的颜色是影响豇豆商业价值的最重要特征之一。为了研究遗传结构，我们首先在田间试验中对六代豇豆的新鲜豆荚颜色进行了评分。之后，从两个高代自交豇豆品系“宝佳”（绿色豆荚颜色，P1）和“奇龙”（紫色豆荚颜色，P2）之间的杂交中获得了 150 个重组个体的 F2 种群。通过SLAF测序构建了基于9,493个单核苷酸多态性的高密度遗传图谱，用于豆荚颜色性状的基因/s作图。我们在一个候选基因区域中观察到 59 个单核苷酸多态性标记，这些标记可能与位于 LG6 上的新鲜豆荚颜色性状相关。pc 的基因座在豇豆基因组的 5 号染色体上得到证实，这对应于编码花青素 5-芳香酰基转移酶和 MYB-90 和 MYB-114 结构域蛋白的基因，在花青素生物合成中起重要作用。最后，开发了 dCAPS 标记，解释了 F2 种群表型的高识别率。这项研究提供了基因组区域的新知识，并将加速有关豇豆和标记辅助选择中的新鲜豆荚颜色 (pc) 特性的遗传改进。