Soybean mosaic virus (SMV) is a major pathogen causing yield loss. Developing soybean plants tolerant or resistant to SMV is important for mitigating the adverse effects of the viral infection. However, most studies have focused on the resistance to normal SMV strains. Thus, investigations of the resistance or tolerance to the novel recombinant SMV strain have been limited. To address the threat of the recombinant SMV, two soybean parent genotypes with contrasting reactions to the recombinant SMV and 211 F9:11 recombinant inbred lines were evaluated under artificial inoculation conditions. The JD12 plants are resistant to the recombinant SMV, whereas HT is highly tolerant, but still susceptible. Genetic analyses suggested that the resistance of JD12 is controlled by a single dominant gene and the tolerance is a quantitative trait. The QTL mapping results revealed one QTL (qTsmv-13) for resistance and two QTLs (qTsmv-2 and qTsmv-3) for tolerance. A comparison between known resistance genes and the QTLs identified in this study suggested that qTsmv-13 and qTsmv-2 may correspond to Rsv1 and Rsv4, respectively, whereas qTsmv-3 represents a newly identified QTL for SMV tolerance. We further delimited qTsmv-3 to an interval of approximately 86 kb with a map-based cloning strategy. Only two of five candidate genes, Glyma.03G00550 and Glyma.03G00570, varied between the parents. Additionally, Glyma.03G00550, which is a multidrug and toxic compound extrusion transporter gene, is the likely candidate gene for qTsmv-3. In summary, our research opens a new avenue for formulating strategies to breed soybean varieties tolerant to SMV.

中文翻译：

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大豆对 SMV 感染耐受性的遗传位点的鉴定和精细定位

大豆花叶病毒 (SMV) 是导致产量损失的主要病原体。开发对 SMV 具有耐受性或抗性的大豆植物对于减轻病毒感染的不利影响很重要。然而，大多数研究都集中在对正常 SMV 菌株的抗性上。因此，对新型重组 SMV 菌株的抗性或耐受性的研究受到限制。为了解决重组 SMV 的威胁，在人工接种条件下评估了对重组 SMV 和 211 F9:11 重组自交系具有对比反应的两种大豆亲本基因型。JD12 植物对重组 SMV 具有抗性，而 HT 具有高度耐受性，但仍然易感。遗传分析表明，JD12 的抗性受单个显性基因控制，耐受性是一个数量性状。QTL定位结果显示1个抗性QTL（qTsmv-13）和2个耐受性QTL（qTsmv-2和qTsmv-3）。已知抗性基因与本研究中鉴定的 QTL 之间的比较表明，qTsmv-13 和 qTsmv-2 可能分别对应于 Rsv1 和 Rsv4，而 qTsmv-3 代表新鉴定的 SMV 耐受性 QTL。我们使用基于图的克隆策略进一步将 qTsmv-3 分隔为大约 86 kb 的间隔。五个候选基因中只有两个，Glyma.03G00550 和 Glyma.03G00570，在父母之间有所不同。此外，Glyma.03G00550 是一种多药和有毒化合物挤出转运蛋白基因，可能是 qTsmv-3 的候选基因。总之，我们的研究开辟了一条新的途径来制定策略来培育对 SMV 耐受的大豆品种。