Gyawali Sanjaya, Bhattarai Gehendra, Correll James C, Shi Ainong, du Toit Lindsey J
Washington State University Mount Vernon Northwestern Washington Research and Extension Center, Mount Vernon, WA, 98273, USA.
PNW Plant Pathology Laboratory, Sakata Seed America Inc, 11857 Bay Ridge Dr., Burlington, WA, 98233, USA.
Sci Rep. 2025 May 3;15(1):15486. doi: 10.1038/s41598-025-98932-x.
Fusarium wilt of spinach, caused by Fusarium oxysporum f. sp. spinaciae (Fos), leads to substantial losses in spinach (Spinacia oleracea) seed production in the only region of the USA suitable for growing spinach seed crops, the maritime Pacific Northwest. Accessions of wild spinach, S. turkestanica, serve as a major source of resistance to multiple spinach diseases. In this study, 84 Spinacia genotypes (all 68 S. turkestanica accessions available publicly and 16 S. oleracea) were evaluated for reactions to Fos at medium and high densities of inoculum comprising a mix of isolates of races 1 and 2, using a factorial experimental design of genotypes (n = 84) and Fos inoculum density (0, 12,500, and 37,500 CFU/ml potting medium) with two replicates. The area under the disease progress curve (AUDPC) calculated for wilt severity 28, 35, and 42 days after planting (DAP) ranged from 0.0 to 11.0 and 1.5 to 13.3 at medium and high inoculum densities, respectively. Of the 68 S. turkestanica accessions, 17 and 8 showed high levels of resistance at medium and high inoculum densities, respectively. Single nucleotide polymorphism (SNP) markers (n = 7,065) identified with genotyping-by-sequencing (GBS) were used for genome wide association studies (GWAS) using multiple models tested with GAPIT and TASSEL software. Twelve SNPs were associated significantly with Fusarium wilt resistance in 10 QTL regions located on chromosomes 1, 3, 4, and 6. SNP S6_38110665 on chromosome 6 was validated across multiple GWAS models and demonstrated a major effect (-2.48 to -2.79) at reducing Fusarium wilt severity. SNP S6_38110665 can be used to introduce Fusarium wilt resistance QTL into cultivated spinach (S. oleracea) using marker-assisted selection, thereby enhancing breeding programs for improved disease resistance.
菠菜枯萎病由尖孢镰刀菌菠菜专化型（Fos）引起，在美国唯一适合种植菠菜种子作物的地区——太平洋西北沿海地区，导致菠菜（菠菜属）种子产量大幅损失。野生菠菜中亚菠菜是多种菠菜病害抗性的主要来源。在本研究中，采用基因型（n = 84）和Fos接种密度（0、12500和37500 CFU/ml盆栽基质）的析因实验设计，对84个菠菜基因型（公开可得的全部68份中亚菠菜种质以及16份普通菠菜）在中等和高密度接种物（包含1号和2号小种分离物混合物）条件下对Fos的反应进行了评估，设置两个重复。种植后28、35和42天（DAP）计算的病情严重程度的病害进展曲线下面积（AUDPC）在中等和高接种密度下分别为0.0至11.0和1.5至13.3。在68份中亚菠菜种质中，分别有17份和8份在中等和高接种密度下表现出高抗性水平。通过简化基因组测序（GBS）鉴定的单核苷酸多态性（SNP）标记（n = 7065）用于全基因组关联研究（GWAS），使用GAPIT和TASSEL软件测试多个模型。12个SNP与位于1、3、4和6号染色体上的10个QTL区域的枯萎病抗性显著相关。6号染色体上的SNP S6_38110665在多个GWAS模型中得到验证，并在降低枯萎病严重程度方面显示出主要效应（-2.48至-2.79）。SNP S6_38110665可用于通过标记辅助选择将枯萎病抗性QTL导入栽培菠菜（普通菠菜），从而加强抗病性改良育种计划。
