Assessment of the taxonomy and diversity of Xanthomonas strains causing bacterial leaf spot of lettuce (BLSL), commonly referred to as Xanthomonas campestris pv. vitians, has been a long-lasting issue which held back the global efforts made to understand this pathogen. In order to provide a sound basis essential to its study, we conducted a polyphasic approach on strains obtained through sampling campaigns or acquired from collections. Results of a multilocus sequence analysis crossed with phenotypic assays revealed that the pathotype strain does not match the description of the nomenspecies provided by Brown in 1918. However, strain LMG 938 = CFBP 8686 does fit this description. Therefore, we propose that it replaces LMG 937 = CFBP 2538 as pathotype strain of X. campestris pv. vitians.

Then, whole-genome based phylogenies and overall genome relatedness indices calculated on taxonomically relevant strains exhibited the intermediate position of X. campestris pv. vitians between closely related species Xanthomonas hortorum and Xanthomonas cynarae. Phenotypic profiles characterized using Biolog microplates did not reveal stable diagnostic traits legitimizing their distinction. Therefore, we propose that X. cynarae Trébaol et al. 2000 emend. Timilsina et al. 2019 is a later heterotypic synonym of X. hortorum, to reclassify X. campestris pv. vitians as X. hortorum pv. vitians comb. nov. and to transfer X. cynarae pathovars in X. hortorum as X. hortorum pv. cynarae comb. nov. and X. hortorum pv. gardneri comb. nov. An emended description of X. hortorum is provided, making this extended species a promising model for the study of Xanthomonas quick adaptation to different hosts.

评估引起生菜细菌性叶斑病（BLSL）的黄单胞菌菌株的分类学和多样性，通常称为黄单胞菌。维提安人，是一个长期存在的问题，阻碍了全球对这种病原体的了解。为了提供对其研究必不可少的良好基础，我们对通过采样活动或从采集中获得的菌株进行了多相研究。多基因座序列分析与表型分析相交的结果表明，该致病型菌株与布朗在1918年提供的命名法的描述不符。但是，LMG 938 = CFBP 8686菌株确实符合该描述。因此，我们建议，它取代了轻机枪937 = CFBP 2538作为致病型菌株X.油菜光伏。vitians。

然后，基于全基因组的系统发育和在分类学上相关菌株上计算的总体基因组相关性指数显示了野油菜X.vv的中间位置。vitians密切相关的物种之间的黄hortorum和黄cynarae。使用Biolog微孔板表征的表型图谱并未显示出使它们的区分合法化的稳定诊断特征。因此，我们建议X. cynaraeTrébaol等。2000年 Timilsina等。2019年是X.hortorum的后来的异型同义词，用于将X.campestris pv重新分类。vitians asX.hortorum光伏 vitians梳。十一月 和转移X. cynarae在pathovars X. hortorum为X. hortorum PV。cynarae梳子。十一月 和X.hortorum pv。加德纳利梳子。十一月 的仔细的校勘描述X. hortorum提供，使这个扩展物种的研究有前途的模型黄单胞菌快速适应不同的主机。