Monnot Severine, Cantet Melissa, Mary-Huard Tristan, Moreau Laurence, Lowdon Rebecca, Van Haesendonck Maurine, Ricard Agnès, Boissot Nathalie
INRAE, Génétique et Amélioration des Fruits et Légumes, 84143, Montfavet, France.
Bayer Crop Science, 13670, Saint-Andiol, France.
Hortic Res. 2022 Aug 25;9:uhac184. doi: 10.1093/hr/uhac184. eCollection 2022.
The mapping and introduction of sustainable resistance to viruses in crops is a major challenge in modern breeding, especially regarding vegetables. We hence assembled a panel of cucumber elite lines and landraces from different horticultural groups for testing with six virus species. We mapped 18 quantitative trait loci (QTL) with a multiloci genome wide association studies (GWAS), some of which have already been described in the literature. We detected two resistance hotspots, one on chromosome 5 for resistance to the cucumber mosaic virus (CMV), cucumber vein yellowing virus (CVYV), cucumber green mottle mosaic virus (CGMMV) and watermelon mosaic virus (WMV), colocalizing with the RDR1 gene, and another on chromosome 6 for resistance to the zucchini yellowing mosaic virus (ZYMV) and papaya ringspot virus (PRSV) close to the putative VPS4 gene location. We observed clear structuring of resistance among horticultural groups due to plant virus coevolution and modern breeding which have impacted linkage disequilibrium (LD) in resistance QTLs. The inclusion of genetic structure in GWAS models enhanced the GWAS accuracy in this study. The dissection of resistance hotspots by local LD and haplotype construction helped gain insight into the panel's resistance introduction history. ZYMV and CMV resistance were both introduced from different donors in the panel, resulting in multiple resistant haplotypes at same locus for ZYMV, and in multiple resistant QTLs for CMV.
在作物中绘制并引入对病毒的可持续抗性是现代育种中的一项重大挑战，尤其是对于蔬菜而言。因此，我们收集了一组来自不同园艺群体的黄瓜优良品系和地方品种，用于六种病毒的测试。我们通过多位点全基因组关联研究（GWAS）绘制了18个数量性状位点（QTL），其中一些已在文献中有所描述。我们检测到两个抗性热点，一个位于5号染色体上，对黄瓜花叶病毒（CMV）、黄瓜叶脉黄化病毒（CVYV）、黄瓜绿斑驳花叶病毒（CGMMV）和西瓜花叶病毒（WMV）具有抗性，与RDR1基因共定位；另一个位于6号染色体上，对西葫芦黄化花叶病毒（ZYMV）和番木瓜环斑病毒（PRSV）具有抗性，靠近假定的VPS4基因位置。由于植物病毒共同进化和现代育种影响了抗性QTL中的连锁不平衡（LD），我们观察到园艺群体之间抗性存在明显的结构差异。在GWAS模型中纳入遗传结构提高了本研究中GWAS的准确性。通过局部LD和单倍型构建对抗性热点进行剖析，有助于深入了解该群体的抗性引入历史。ZYMV和CMV抗性均从该群体中的不同供体引入，导致ZYMV在同一基因座出现多个抗性单倍型，CMV出现多个抗性QTL。
