Lai Ruiqiang, Xia Yanshi, Li Ronghua, Yuan Qinghua, Zhao Weicai, Siddique Kadambot H M, Guo Peiguo
Guangdong Provincial Key Laboratory of Plant Adaptation and Molecular Design, School of Life Sciences, Guangzhou University, Guangzhou, 510006, China.
College of Agriculture & Biology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China.
Heliyon. 2024 Oct 3;10(19):e38939. doi: 10.1016/j.heliyon.2024.e38939. eCollection 2024 Oct 15.
Identifying molecular markers linked to tobacco bacterial wilt resistance is crucial for developing resistant tobacco varieties, thereby enhancing tobacco production and quality. In this two-year study, we evaluated the tobacco bacterial wilt disease index (TBWDI) in a mapping population of 78 tobacco accessions using SSR/InDel markers across 1377 marker loci. Two association models, GLM_Q and MLM_Q + Kinship, were used for association analysis. By considering multiple environments, selection thresholds, and phenotype values, we identified 19 reliable marker loci (P = 7.07-E05-4.98-E02) that explained 5.37-19.10 % of the phenotypic variation. Among these, we selected 11 accessions with high resistance to tobacco bacterial wilt, each containing at least one excellent locus. The models predicted five hybrid combinations whose offspring aggregated additional excellent loci. Additionally, one locus was identified during quantitative trait loci mapping, with accessions carrying this locus exhibiting significantly different TBWDI values from those without it, confirming its reliability and stability. A candidate gene (LOC107795335) was also identified downstream at 17.58 Kbp of the locus. Our study pinpointed reliable loci associated with bacterial wilt resistance, identified important materials for breeding resistant tobacco varieities, and predicted the best hybrid combinations for low disease indexes. The results of our study offer invaluable theoretical insights for breeding varieties with high and stable resistance.
鉴定与烟草青枯病抗性相关的分子标记对于培育抗性烟草品种至关重要，从而提高烟草产量和品质。在这项为期两年的研究中，我们使用SSR/InDel标记在1377个标记位点上对78份烟草种质的作图群体进行了烟草青枯病病情指数（TBWDI）评估。使用GLM_Q和MLM_Q + 亲缘关系两种关联模型进行关联分析。通过考虑多种环境、选择阈值和表型值，我们鉴定出19个可靠的标记位点（P = 7.07-E05-4.98-E02），这些位点解释了5.37%-19.10%的表型变异。其中，我们选择了11份对烟草青枯病具有高抗性的种质，每份种质至少含有一个优良位点。模型预测了五个杂交组合，其后代聚合了额外的优良位点。此外，在数量性状基因座定位过程中鉴定出一个位点，携带该位点的种质与不携带该位点的种质相比，TBWDI值存在显著差异，证实了其可靠性和稳定性。在该位点下游17.58 Kbp处还鉴定出一个候选基因（LOC107795335）。我们的研究确定了与青枯病抗性相关的可靠位点，鉴定出了抗青枯病烟草品种的重要育种材料，并预测了低病情指数的最佳杂交组合。我们的研究结果为培育高抗性和稳定抗性的品种提供了宝贵的理论见解。
