Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China.
Int J Mol Sci. 2021 Jan 11;22(2):653. doi: 10.3390/ijms22020653.
The swollen root is an important agronomic trait and is a determinant of yield for turnips, which are cultivated as both vegetables and fodder. However, the genetic mechanism of swollen root formation is poorly understood. In this study, we analyzed the F and BCP populations derived from a cross between "10601" (European turnip with swollen root, ssp. , AA, 2n = 2× = 20) and "10603" (Chinese cabbage with normal root, ssp. , AA, 2n = 2× = 20), and suggested that the swollen root is a quantitative trait. Two major quantitative trait loci (QTLs), (Fleshy root 1.1) and (Fleshy root 7.1), were identified by QTL-seq analysis and further confirmed by QTL mapping in F and BCP populations. The QTL with a likelihood of odd (LOD) of 7.01 explained 17.2% of the total phenotypic variations for root diameter and the QTL explained 23.0% (LOD = 9.38) and 31.0% (LOD = 13.27) of the total phenotypic variations in root diameter and root weight, respectively. After a recombinant screening, the major QTL was further narrowed down to a 220 kb region containing 47 putative genes. A candidate gene, , which is a homolog of that plays an essential role in cell adhesion and disorganized tumor-like formation in , was identified in this region. In addition, expression and parental allele analysis supported that was a possible candidate gene of QTL for swollen root formation in turnip. Our research may provide new insight into the molecular mechanism of swollen root formation in root crops.
膨大块根是一个重要的农艺性状，是萝卜产量的决定因素，萝卜既可以作为蔬菜也可以作为饲料种植。然而，膨大块根形成的遗传机制还知之甚少。在这项研究中，我们分析了来自“10601”（欧洲萝卜，膨大块根， ssp. ，AA，2n = 2× = 20）和“10603”（中国白菜，正常块根， ssp. ，AA，2n = 2× = 20）杂交后代的 F 和 BCP 群体，并提出膨大块根是一个数量性状。通过 QTL-seq 分析鉴定到两个主要的数量性状位点（QTL）， （Fleshy root 1.1）和 （Fleshy root 7.1），并通过 F 和 BCP 群体的 QTL 作图进一步验证。QTL 解释了根直径总表型变异的 17.2%，LOD 值为 7.01；QTL 解释了根直径和根重总表型变异的 23.0%（LOD = 9.38）和 31.0%（LOD = 13.27）。经过重组筛选，主效 QTL 进一步缩小到包含 47 个推定基因的 220 kb 区域。在这个区域中鉴定到一个候选基因 ，它是 的同源基因，在 中发挥着细胞黏附和紊乱肿瘤样形成的重要作用。此外，表达和亲本等位基因分析支持 是萝卜膨大块根形成 QTL 的候选基因。我们的研究可能为块根作物膨大块根形成的分子机制提供新的见解。
