Two novel and adjacent genomics and candidate genes for bacterial wilt resistance were identified on chromosome B02 in peanut variety Zhonghua 6 using both traditional QTL mapping and QTL-seq methods. Peanut (Arachis hypogaea) is an important oilseed crop worldwide. Utilization of genetic resistance is the most economic and effective approach to control bacterial wilt, one of the most devastating plant diseases, in peanut production. To accelerate the genetic improvement of bacterial wilt resistance (BWR) in peanut breeding programs, quantitative trait locus (QTL) mapping has been conducted for two resistant varieties. In this context, we deployed linkage mapping as well as sequencing-based mapping approach, QTL-seq, to identify genomic regions and candidate genes for BWR in another highly resistant variety Zhonghua 6. The recombination inbred line population (268 progenies) from the cross Xuhua 13 × Zhonghua 6 was used in BWR evaluation across five environments. QTL mapping using both SSR- and SNP-based genetic maps identified a stable QTL (qBWRB02-1) on chromosome B02 with 37.79-78.86% phenotypic variation explained (PVE) across five environments. The QTL-seq facilitated further dissection of qBWRB02-1 into two adjacent genomic regions, qBWRB02-1-1 (2.81-4.24 Mb) and qBWRB02-1-2 (6.54-8.75 Mb). Mapping of newly developed Kompetitive allele-specific PCR (KASP) markers on the genetic map confirmed their stable expressions across five environments. The effects of qBWRB02-1-1 (49.43-68.86% PVE) were much higher than qBWRB02-1-2 (3.96-6.48% PVE) and other previously reported QTLs. Nineteen putative candidate genes affected by 49 non-synonymous SNPs were identified for qBWRB02-1-1, and ten of them were predicted to code for disease resistance proteins. The major and stable QTL qBWRB02-1-1 and validated KASP markers could be deployed in genomics-assisted breeding (GAB) to develop improved peanut varieties with enhanced BWR.

中文翻译：

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花生品种中华 6 号染色体 B02 上控制青枯病抗性的两个新的相邻 QTL。

使用传统的 QTL 作图和 QTL-seq 方法在花生品种中华 6 号染色体 B02 上鉴定了两个新的和相邻的抗青枯病基因组和候选基因。花生 (Arachis hypogaea) 是世界范围内重要的油料作物。利用遗传抗性是控制青枯病的最经济有效的方法，青枯病是花生生产中最具破坏性的植物病害之一。为了加速花生育种计划中青枯病抗性（BWR）的遗传改良，对两个抗性品种进行了数量性状位点（QTL）作图。在这种情况下，我们部署了连锁作图以及基于测序的作图方法 QTL-seq，以识别另一个高抗性品种中华 6 中 BWR 的基因组区域和候选基因。来自杂交旭华13×中华6的重组自交系种群（268个后代）用于五个环境的BWR评估。使用基于 SSR 和 SNP 的遗传图谱的 QTL 作图在染色体 B02 上确定了一个稳定的 QTL (qBWRB02-1)，在五个环境中具有 37.79-78.86% 的表型变异解释 (PVE)。QTL-seq 有助于将 qBWRB02-1 进一步分解为两个相邻的基因组区域，qBWRB02-1-1 (2.81-4.24 Mb) 和 qBWRB02-1-2 (6.54-8.75 Mb)。新开发的竞争性等位基因特异性 PCR (KASP) 标记在遗传图谱上的定位证实了它们在五种环境中的稳定表达。qBWRB02-1-1 (49.43-68.86% PVE) 的效果远高于 qBWRB02-1-2 (3.96-6.48% PVE) 和其他先前报道的 QTL。为 qBWRB02-1-1 鉴定了 19 个受 49 个非同义 SNP 影响的推定候选基因，预测其中 10 个编码抗病蛋白。主要且稳定的 QTL qBWRB02-1-1 和经过验证的 KASP 标记可用于基因组学辅助育种 (GAB)，以开发具有增强 BWR 的改良花生品种。