Fredua-Agyeman Rudolph, Yu Zhiyu, Hwang Sheau-Fang, Strelkov Stephen E
Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada.
Front Plant Sci. 2020 Jun 12;11:742. doi: 10.3389/fpls.2020.00742. eCollection 2020.
Rutabaga [ ssp. (L.) Hanelt] is reported to be an excellent source of clubroot () resistance genes. In this study, 124 rutabaga accessions from the Nordic countries (Norway, Sweden, Finland, Denmark, and Iceland) were evaluated for their reaction to five single-spore isolates representing pathotypes 2F, 3H, 5I, 6M, and 8N and 12 field isolates representing pathotypes 2B, 3A, 3O, 5C, 5G, 5K, 5L, 5X (two isolates, L-G2 and L-G3), 8E, 8J, and 8P. The accessions were also genotyped using a 15K Brassica SNP array and 60 PCR-based primers linked to previously identified clubroot resistance genes. Six thousand eight hundred sixty-one SNP markers were retained after filtering with TASSEL 5.0, and used to evaluate four general linear models (GLM) and four mixed linear models (MLM). The PCA + K and Q + K MLM models gave the minimal deviance of the observed from the expected distribution in quantile-quantile plots, and hence were used for SNP-clubroot association analyses. In addition, 108 alleles derived from the PCR-based markers and the phenotypic data were analyzed with the PCA + K model. Forty-five SNPs and four PCR-based markers were identified to be associated strongly with resistance to isolates representing 13 pathotypes (2F, 3H, 5I, 6M, 8N, 2B, 3A, 3O, 5C, 5G, 5K, 5L, and 8P). These markers revealed the top and bottom segments of rutabaga chromosome A03 and the middle segment of chromosome A08 as genomic hotspots associated with resistance to the different pathotypes.
芜菁甘蓝（芜菁甘蓝亚种（L.）哈内尔特）据报道是根肿病抗性基因的优良来源。在本研究中，对来自北欧国家（挪威、瑞典、芬兰、丹麦和冰岛）的124份芜菁甘蓝种质进行了评估，以确定它们对代表2F、3H、5I、6M和8N致病型的5个单孢分离株以及代表2B、3A、3O、5C、5G、5K、5L、5X（两个分离株，L-G2和L-G3）、8E、8J和8P致病型的12个田间分离株的反应。还使用15K甘蓝型油菜SNP芯片和与先前鉴定的根肿病抗性基因相关的60对基于PCR的引物对这些种质进行了基因分型。使用TASSEL 5.0过滤后保留了6861个SNP标记，并用于评估四个一般线性模型（GLM）和四个混合线性模型（MLM）。PCA + K和Q + K MLM模型在分位数-分位数图中给出了观察值与预期分布的最小偏差，因此用于SNP-根肿病关联分析。此外，使用PCA + K模型分析了来自基于PCR的标记的108个等位基因和表型数据。鉴定出45个SNP和4个基于PCR的标记与对代表13种致病型（2F、3H、5I、6M、8N、2B、3A、3O、5C、5G、5K、5L和8P）的分离株的抗性密切相关。这些标记揭示了芜菁甘蓝A03染色体的顶部和底部区段以及A08染色体的中间区段是与对不同致病型抗性相关的基因组热点。
