Li Dan, Song Xi, Yang Fang
School of Agriculture and Bioengineering, Longdong University, Qingyang, Gansu, China.
Front Plant Sci. 2025 Jun 17;16:1611008. doi: 10.3389/fpls.2025.1611008. eCollection 2025.
Wheat streak mosaic virus (WSMV), one of the major pathogens affecting global wheat production, causes severe yield losses. Although its global diversification has been reported, the evolutionary dynamics and phylogeographic patterns of WSMV remain poorly understood. In the present study, we systematically investigated the global distribution of WSMV by integrating genomic sequences and literature reports. Furthermore, we analyzed the evolutionary dynamics and phylogeography of WSMV using 104 complete genomes and 218 coat protein (CP) gene sequences. Our results revealed that WSMV is currently spreading across 26 countries on six continents. Maximum likelihood (ML) phylogenetic analyses delineated four genotypes: Genotype I (Mexican lineage), Genotype II (Iranian-specific lineage), Genotype III (Eurasian-North American lineage), and Genotype IV (U.S.-Australian-Iranian lineage). Bayesian phylodynamic analysis estimated a mean evolutionary rate of 3.023 × 10 substitution/site/year (95% HPD: 1.945 × 10-4.187 × 10), and suggested that WSMV may have emerged in Iran, with the time to the most recent common ancestor (tMRCA) around 1700 (95% HPD: 1521-1850), although the relatively weak temporal signal limits precise timing (R² = 0.0585). Hierarchical tMRCA estimates revealed progressive diversification: Turkey and the United States at 1730 (95% HPD: 1580-1854), European countries at 1952 (95% HPD: 1915-1983), Kazakhstan at 1949 (95% HPD: 1911-1983), Australia at 1972 (95% HPD: 1953-1991), and Brazil at 1994 (95% HPD: 1981-2005). Bayesian phylogeographic reconstruction suggested Iran as a likely origin based on current data, with dispersal to the United States in the mid-19th century (1852-1887; Bayes factors (BF) = 5.26, posterior probability (PP) = 0.48) and to Turkey in the 20th century (1909-1942; BF = 65.76, PP = 0.92), both of which subsequently served as secondary hubs for global dissemination. The findings that WSMV has undergone persistent evolutionary diversification over extended temporal scales, and continues to spread globally, providing a framework for enhanced surveillance and control strategies.
小麦线条花叶病毒（WSMV）是影响全球小麦生产的主要病原体之一，会导致严重的产量损失。尽管已有其全球多样性的报道，但WSMV的进化动态和系统发育地理模式仍知之甚少。在本研究中，我们通过整合基因组序列和文献报告，系统地调查了WSMV的全球分布。此外，我们使用104个完整基因组和218个外壳蛋白（CP）基因序列分析了WSMV的进化动态和系统发育地理学。我们的结果显示，WSMV目前正在六大洲的26个国家传播。最大似然（ML）系统发育分析划分出四个基因型：基因型I（墨西哥谱系）、基因型II（伊朗特有的谱系）、基因型III（欧亚 - 北美谱系）和基因型IV（美国 - 澳大利亚 - 伊朗谱系）。贝叶斯系统发育动力学分析估计平均进化速率为3.023×10⁻⁴替换/位点/年（95%最高后验密度区间：1.945×10⁻⁴ - 4.187×10⁻⁴），并表明WSMV可能起源于伊朗，最近共同祖先时间（tMRCA）约为1700年（95%最高后验密度区间：1521 - 1850），尽管相对较弱的时间信号限制了精确的时间确定（R² = 0.0585）。分层tMRCA估计揭示了渐进的多样化：土耳其和美国在1730年（95%最高后验密度区间：1580 - 1854），欧洲国家在1952年（95%最高后验密度区间：1915 - 1983），哈萨克斯坦在1949年（95%最高后验密度区间：1911 - 1983），澳大利亚在1972年（95%最高后验密度区间：1953 - 1991），巴西在1994年（95%最高后验密度区间：1981 - 2005）。贝叶斯系统发育地理重建基于当前数据表明伊朗可能是起源地，在19世纪中叶传播到美国（1852 - 1887；贝叶斯因子（BF） = 5.26，后验概率（PP） = 0.48），在20世纪传播到土耳其（1909 - 1942；BF = 65.76，PP = 0.92），这两个地方随后都成为了全球传播的二级枢纽。WSMV在长时间尺度上经历了持续的进化多样化并继续在全球传播，这一发现为加强监测和控制策略提供了框架。
