Pelikan Audrey, Goldman Irwin L
Department of Plant and Agroecosystem Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA.
Plant Genome. 2025 Mar;18(1):e70014. doi: 10.1002/tpg2.70014.
Sweetness is a main component of the table beet (Beta vulgaris L.) flavor profile and a key determinant of its market success for fresh consumption. Total dissolved solids (TDS) is a proxy for sugar content in produce and are easily measured through a refractometer, making TDS valuable in breeding programs focused on increasing sweetness. A diversity panel of 238 accessions from the Beta vulgaris crop complex and wild relatives was assembled and genotyped using genotyping-by-sequencing, yielding 10,237 single nucleotide polymorphisms (SNPs) from 226 full panel accessions and 9,847 SNPs from table beet only accessions after filtering. The panel was phenotyped in field trials over 2 years and mean values were adjusted using best linear unbiased estimates. TDS levels varied among crop types and a broad-sense heritability of 0.90 indicated that phenotypic differences can be attributed in large part to genetic variation. A genome-wide association study (GWAS) uncovered four quantitative trait loci (QTLs) identified across multiple models to significantly associate with TDS. A QTL on chromosome 2 was consistently identified among GWAS models, explaining 12.1%-62.6% of the phenotypic variation in the full panel. Bevul.2G176300, a gene directly involved in the sucrose biosynthesis pathway, was located downstream the significant marker. A second QTL identified on chromosome 7 revealed QTL alleles that may differentiate between table beet accessions, explaining nearly half the phenotypic variation, and is the first QTL reported in association with TDS unique to table beet. The QTL described can be used to efficiently breed for higher TDS levels in Beta vulgaris, avoiding intercrop type crosses and linkage drag.
甜度是食用甜菜（Beta vulgaris L.）风味的主要组成部分，也是其鲜食市场成功的关键决定因素。总溶解固体（TDS）是农产品中糖分含量的替代指标，可通过折射仪轻松测量，这使得TDS在专注于提高甜度的育种计划中具有重要价值。我们组建了一个由238份来自甜菜作物复合体及其野生近缘种的种质组成的多样性群体，并通过简化基因组测序进行基因分型，经过筛选后，从226份全群体种质中获得了10237个单核苷酸多态性（SNP），从仅食用甜菜种质中获得了9847个SNP。该群体在两年的田间试验中进行了表型分析，并使用最佳线性无偏估计对平均值进行了调整。TDS水平在不同作物类型间存在差异，广义遗传力为0.90，表明表型差异在很大程度上可归因于遗传变异。全基因组关联研究（GWAS）发现了四个在多个模型中均被鉴定出与TDS显著相关的数量性状位点（QTL）。在GWAS模型中，2号染色体上的一个QTL始终被鉴定出来，解释了全群体中12.1%-62.6%的表型变异。直接参与蔗糖生物合成途径的基因Bevul.2G176300位于显著标记的下游。在7号染色体上鉴定出的第二个QTL揭示了可能区分食用甜菜种质的QTL等位基因，解释了近一半的表型变异，这是首次报道的与食用甜菜特有的TDS相关的QTL。所描述的QTL可用于在甜菜中高效培育更高TDS水平的品种，避免种间杂交和连锁累赘。
