Tian Xiaocui, Zhang Kaixin, Liu Shulin, Sun Xu, Li Xiyu, Song Jie, Qi Zhongying, Wang Yue, Fang Yanlong, Wang Jiajing, Jiang Sitong, Yang Chang, Tian Zhixi, Li Wen-Xia, Ning Hailong
Key Laboratory of Soybean Biology, Ministry of Education, Northeast Agricultural University, Harbin, China.
Key Laboratory of Soybean Biology and Breeding/Genetics, Ministry of Agriculture, Northeast Agricultural University, Harbin, China.
Front Genet. 2020 Jun 25;11:563. doi: 10.3389/fgene.2020.00563. eCollection 2020.
Soybean varieties suitable for high planting density allow greater yields. However, the seed protein and oil contents, which determine the value of this crop, can be influenced by planting density. Thus, it is important to understand the genetic basis of the responses of different soybean genotypes to planting density. In this study, we quantified the protein and oil contents in a four-way recombinant inbred line (FW-RIL) soybean population under two planting densities and the response to density. We performed quantitative trait locus (QTL) mapping using a single nucleotide polymorphism (SNP) linkage map generated by inclusive composite interval mapping. We identified 14 QTLs for protein content and 17 for oil content at a planting density of 2.15 × 10 plant/ha (D1) and 14 QTLs for protein content and 20 for oil content at a planting density 3.0 × 10 plant/ha (D2). Among the QTLs detected, two oil-content QTLs was detected at both plant densities. In addition, we identified 38 QTLs for the responses of protein and oil contents to planting density. Of the QTLs detected, 70 were identified in previous studies, while 33 were newly identified. Fourty-five QTLs accounted for over 10% of the phenotypic variation of the corresponding trait, based on 23 QTLs at a marker interval distance of ~600 kb detected under different densities and with the responses to density difference. Pathway analysis revealed four candidate genes involved in protein and oil biosynthesis/metabolism. These results improve our understanding of the genetic underpinnings of protein and oil biosynthesis in soybean, laying the foundation for enhancing protein and oil contents and increasing yields in soybean.
适合高密度种植的大豆品种能实现更高产量。然而，决定这种作物价值的种子蛋白质和油含量会受到种植密度的影响。因此，了解不同大豆基因型对种植密度响应的遗传基础很重要。在本研究中，我们对一个四交重组自交系（FW-RIL）大豆群体在两种种植密度下的蛋白质和油含量以及对密度的响应进行了量化。我们使用通过包容性复合区间作图生成的单核苷酸多态性（SNP）连锁图谱进行数量性状位点（QTL）定位。我们在种植密度为2.15×10株/公顷（D1）时鉴定出14个蛋白质含量QTL和17个油含量QTL，在种植密度为3.0×10株/公顷（D2）时鉴定出14个蛋白质含量QTL和20个油含量QTL。在检测到的QTL中，有两个油含量QTL在两种种植密度下均被检测到。此外，我们鉴定出38个蛋白质和油含量对种植密度响应的QTL。在检测到的QTL中，70个在先前研究中已被鉴定，而33个是新鉴定的。基于在不同密度下检测到的标记区间距离约为600 kb且对密度差异有响应的23个QTL，45个QTL占相应性状表型变异的10%以上。通路分析揭示了四个参与蛋白质和油生物合成/代谢的候选基因。这些结果增进了我们对大豆蛋白质和油生物合成遗传基础的理解，为提高大豆蛋白质和油含量及增加产量奠定了基础。
