Wang Lifang, Zhou Xiaojing, Ren Xiaoping, Huang Li, Luo Huaiyong, Chen Yuning, Chen Weigang, Liu Nian, Liao Boshou, Lei Yong, Yan Liying, Shen Jinxiong, Jiang Huifang
Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, China.
College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.
Front Genet. 2018 Dec 18;9:652. doi: 10.3389/fgene.2018.00652. eCollection 2018.
Bacterial wilt (BW) is one of the important diseases limiting the production of peanut ( L.) worldwide. The sufficient precise information on the quantitative trait loci (QTL) for BW resistance is essential for facilitating gene mining and applying in molecular breeding. Cultivar Yuanza 9102 is BW resistant, bred from wide cross between cultivated peanut Baisha 1016 and a wild diploid peanut species with BW resistance. In this study, we aim to map the major QTLs related to BW-resistance in Yuanza 9102. A high density SNP-based genetic linkage map was constructed through double-digest restriction-site-associated DNA sequencing (ddRADseq) technique based on Yuanza 9102 derived recombinant inbred lines (RILs) population. The map contained 2,187 SNP markers distributed on 20 linkage groups (LGs) spanning 1566.10 cM, and showed good synteny with AA genome from and BB genome from . Phenotypic frequencies of BW resistance among RIL population showed two-peak distribution in four environments. Four QTLs explaining 5.49 to 23.22% phenotypic variance were identified to be all located on chromosome B02. The major QTL, (12.17-23.33% phenotypic variation explained), was detected in three environments showing consistent and stable expression. Furthermore, there was positive additive effect among these major and minor QTLs. The major QTL region was mapped to a region covering 2.3 Mb of the pseudomolecule B02 of which resides in 21 nucleotide-binding site -leucine-rich repeat (NBS-LRR) encoding genes. The result of the major stable QTL () not only offers good foundation for discovery of BW resistant gene but also provide opportunity for deployment of the QTL in marker-assisted breeding in peanut.
青枯病是限制全球花生生产的重要病害之一。关于抗青枯病数量性状位点（QTL）的充分精确信息对于促进基因挖掘和应用于分子育种至关重要。远杂9102品种对青枯病具有抗性，它是由栽培花生白沙1016与具有抗青枯病能力的野生二倍体花生品种进行远缘杂交培育而成。在本研究中，我们旨在定位远杂9102中与抗青枯病相关的主要QTL。基于远杂9102衍生的重组自交系（RIL）群体，通过双酶切限制性位点关联DNA测序（ddRADseq）技术构建了一个高密度的基于SNP的遗传连锁图谱。该图谱包含2187个SNP标记，分布在20个连锁群（LG）上，跨度为1566.10 cM，与 的AA基因组和 的BB基因组具有良好的共线性。RIL群体中抗青枯病的表型频率在四个环境中呈双峰分布。鉴定出四个解释5.49%至23.22%表型变异的QTL，它们均位于B02染色体上。主要QTL （解释12.17 - 23.33%的表型变异）在三个环境中被检测到，表现出一致且稳定的表达。此外，这些主要和次要QTL之间存在正向加性效应。主要QTL区域被定位到 假分子B02上一个覆盖2.3 Mb的区域，该区域存在21个编码核苷酸结合位点 - 富含亮氨酸重复序列（NBS - LRR）的基因。主要稳定QTL（ ）的结果不仅为发现抗青枯病基因提供了良好基础，也为该QTL在花生标记辅助育种中的应用提供了机会。
