Ralstonia solanacearum species complex is a highly destructive bacterial plant pathogen recognized as a group of genotypically-diverse strains with broad geographic distribution and wide host range. Strains are divided into four phylotypes (I, II, III and IV) relating to their geographical origins. Based on the polyphasic approach, phylotypes I and III have been reclassified as R. pseudosolanacearum, phylotype IV as R. syzygii species and phylotype II as R. solanacearum. The large data sets of whole genome sequences for the members of R. solanacearum allow us to discover novel molecular markers to evaluate the phylogenetic relationships within this species. In the phylogenetic tree based on concatenated amino acid sequences of 57 housekeeping genes, members of R. solanacearum species complex formed strongly supported clades that clearly distinguished as R. solanacearum, R. pseudosolanacearum and R. syzygii species. In this study, the conserved signature indels (CSIs) which are specifically present in protein sequences and can be used to differentiate various groups of Ralstonia species are reported. Comparative analysis of whole protein sequences from the three species has identified seven CSIs that are specific to R. solanacearum (phylotype II), 6 CSIs specific to R. pseudosolanacearum strains (phylotype I and III) and five CSIs that are specifically shared by members of R. syzygii (phylotype IV). These CSIs are flanked by conserved sequence regions, providing highly specific tools for identification of previously known or novel strains of these species.

青枯雷尔氏菌物种复合物是一种高度破坏性的细菌植物病原体，被认为是一组基因型多样的菌株，具有广泛的地理分布和广泛的寄主范围。菌株根据其地理起源分为四种系统型（I，II，III和IV）。基于该多相方法中，种系型I和III已经被重新分类为R. pseudosolanacearum，种系型IV为R. syzygii物种和种系型II作为青枯菌。青枯菌成员全基因组序列的大数据集让我们发现新颖的分子标记来评估该物种内的系统发育关系。在基于57个管家基因级联的氨基酸序列的系统树，成员青枯菌物种复杂形成强烈支持进化枝，清楚地区别为青枯雷尔氏菌，R. pseudosolanacearum和R. syzygii物种。在这项研究中，据报道存在于蛋白质序列中的保守签名插入/缺失（CSI），可用于区分各种罗氏菌属。对来自这三个物种的全蛋白序列的比较分析，确定了七个针对青枯菌的CSIs（系统型II），特异假单胞菌菌株的6种CSI （系统型I和III）和由syzygii成员特异性共享的5种CSI （系统型IV）。这些CSI两侧是保守的序列区域，为鉴定这些物种的先前已知或新颖的菌株提供了高度特异性的工具。