Sorghum [Sorghum bicolor (L.) Moench] is an important food crop with a diverse gene pool residing in its wild relatives. A total of 15 sorghum accessions from the unexploited wild gene pool of the Sorghum genus, representing the five subgenera, were sequenced, and the complete chloroplast genomes and 99 common single-copy concatenated nuclear genes were assembled. Annotation of the chloroplast genomes identified a total of 81 protein-coding genes, 38 tRNA, and four rRNA genes. The gene content and gene order among the species was identical. A total of 153 nonsynonymous amino acid changes in 40 genes were identified across the species. Phylogenetic analysis of both the whole chloroplast genome and nuclear genes revealed a similar topology with two distinct clades within the genus. The species within the subgenera Eusorghum, Chaetosorghum, and Heterosorghum clustered in one clade, whereas the species within the subgenera Parasorghum and Stiposorghum clustered in a second clade. However, the subgenera Parasorghum and Stiposorghum were not monophyletic, suggesting the need for further research to resolve the relationships within this group. The close relationship between the two monotypic subgenera Chaetosorghum and Heterosorghum suggests that species within these subgenera could be considered as one group. This analysis provides an improved understanding of the genetic relationships within the Sorghum genus and defines diversity in wild sorghum species that may be useful for crop improvement.

中文翻译：

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基于叶绿体和核基因测序的高粱属系统发育关系

高粱 [ Sorghum bicolor  (L.) Moench] 是一种重要的粮食作物，其野生近缘种具有多样化的基因库。来自未开发的高粱野生基因库的总共 15 个高粱种质对代表五个亚属的属进行了测序，并组装了完整的叶绿体基因组和99个常见的单拷贝串联核基因。叶绿体基因组的注释确定了总共 81 个蛋白质编码基因、38 个 tRNA 和 4 个 rRNA 基因。物种间的基因含量和基因顺序是相同的。在整个物种中，共鉴定了 40 个基因中的 153 个非同义氨基酸变化。整个叶绿体基因组和核基因的系统发育分析揭示了一个相似的拓扑结构，该属内有两个不同的进化枝。Eusorghum、Chaetosorghum和Heterosorghum亚属中的物种聚集在一个进化枝中，而Parasorghum亚属中的物种和Stiposorghum聚集在第二个进化枝中。然而，副高粱和针刺高粱亚属不是单系的，这表明需要进一步研究来解决该组内的关系。两个单型亚属Chaetosorghum和Heterosorghum之间的密切关系表明，这些亚属中的物种可以被视为一个组。该分析提供了对高粱属内遗传关系的更好理解，并确定了可能对作物改良有用的野生高粱物种的多样性。