Morelli Massimiliano, D'Attoma Giusy, Saldarelli Pasquale, Minafra Angelantonio
Consiglio Nazionale delle Ricerche, Istituto per la Protezione Sostenibile delle Piante, Sede Secondaria di Bari, 70126 Bari, Italy.
Pathogens. 2024 Nov 15;13(11):1001. doi: 10.3390/pathogens13111001.
Wisteria vein mosaic virus (WVMV, ), a virus belonging to the genus , is responsible for Wisteria vein mosaic disease (WMD), a severe disease that affects , a genus of garden plants acclaimed worldwide. Although probably originating in the Far East, WVMV infection was first reported in the US, and subsequently in numerous countries. Following the first molecular detection of an Italian isolate, WVMV Bari, its full-length genome was achieved using NGS barcoding technology. A PhyML phylogenetic analysis, supported by clustering algorithm validation, identified a clear separation between two phylogroups. One major clade comprised WVMV strains isolated from spp. A second clade grouped three highly divergent strains, at the borderline species threshold, all found in non-wisteria hosts. Relying on a Relative Time Dated Tips (RTDT) molecular clock, the first emergence of WVMV clades has been traced back to around the 17th century. A network inference analysis confirmed the sharp separation between the two host-related phylogroups, also highlighting the presence of potential intermediate variants. Inter-population genetic parameters revealed a very high genetic differentiation in both populations, which was made reliable by statistically significant permutation tests. The migrant number (m) and fixation index () evidenced a restricted gene flow and strong population structures. According to the d/d ratio and negative neutrality tests, it was derived that purifying selection at the expense of non-silent variants is underway within WVMV populations. Targeting WVMV evolutionary traits, the present effort raised interesting questions about the underestimated potential of this culpably neglected species to spread in economically relevant crops. The main intention of our study is, therefore, to propose an evolution-based analysis approach that serves as a case study to investigate how other potyviruses or newly emerging viruses may spread.
紫藤脉花叶病毒（WVMV）属于 属病毒，可引发紫藤脉花叶病（WMD），该病会影响紫藤属植物，紫藤属是一种在全球备受赞誉的园林植物属。尽管WVMV可能起源于远东地区，但该病毒感染最早是在美国被报道，随后在许多国家也有发现。在首次对意大利分离株WVMV Bari进行分子检测后，利用二代测序条形码技术获得了其全长基因组。通过聚类算法验证支持的PhyML系统发育分析，确定了两个系统发育组之间的明显分离。一个主要分支包含从 属植物中分离出的WVMV菌株。第二个分支将三个高度不同的菌株归为一组，这些菌株处于临界物种阈值，均在非紫藤宿主中发现。依靠相对时间标定末端（RTDT）分子钟，WVMV分支的首次出现可追溯到17世纪左右。网络推断分析证实了两个宿主相关系统发育组之间的明显分离，同时也突出了潜在中间变体的存在。种群间遗传参数显示两个种群中均存在非常高的遗传分化，这通过具有统计学意义的置换检验得以证实。迁移数（m）和固定指数（）表明基因流动受限且种群结构强烈。根据dN/dS比率和负向中性检验，得出在WVMV种群中正在进行以非沉默变体为代价的纯化选择。针对WVMV的进化特征，目前的研究提出了一些有趣的问题，即这种被严重忽视的物种在经济相关作物中传播的潜在可能性被低估了。因此，我们研究的主要目的是提出一种基于进化的分析方法，作为一个案例研究，以探讨其他马铃薯Y病毒或新出现的病毒可能如何传播。
