PDF(Pubmed)
Abstract：
Bromus (Poaceae Bromeae) is a forage grass with high adaptability and ecological and economic value. Here, we sequenced Bromus ciliatus, Bromus benekenii, Bromus riparius, and Bromus rubens chloroplast genomes and compared them with four previously described species. The genome sizes of Bromus species ranged from 136,934 bp (Bromus vulgaris) to 137,189 bp (Bromus ciliates, Bromus biebersteinii), with a typical quadripartite structure. The studied species had 129 genes, consisting of 83 protein-coding, 38 tRNA-coding, and 8 rRNA-coding genes. The highest GC content was found in the inverted repeat (IR) region (43.85-44.15%), followed by the large single-copy (LSC) region (36.25-36.65%) and the small single-copy (SSC) region (32.21-32.46%). There were 33 high-frequency codons, with those ending in A/U accounting for 90.91%. A total of 350 simple sequence repeats (SSRs) were identified, with single-nucleotide repeats being the most common (61.43%). A total of 228 forward and 141 palindromic repeats were identified. No reverse or complementary repeats were detected. The sequence identities of all sequences were very similar, especially with respect to the protein-coding and inverted repeat regions. Seven highly variable regions were detected, which could be used for molecular marker development. The constructed phylogenetic tree indicates that Bromus is a monophyletic taxon closely related to Triticum. This comparative analysis of the chloroplast genome of Bromus provides a scientific basis for species identification and phylogenetic studies.
摘要：
Bromus是一种具有较高适应性和生态经济价值的牧草。这里,我们对Bromusciliatus进行了测序，Bromusbenekenii,Bromusriparius,和Bromusrubens叶绿体基因组，并将其与先前描述的四个物种进行比较。Bromus物种的基因组大小范围从136,934bp（普通Bromusvulgaris）到137,189bp（Bromus纤毛虫，Bromusbiebersteinii)，具有典型的四方结构。研究的物种有129个基因，由83个蛋白质编码组成，38tRNA编码，和8个rRNA编码基因。GC含量最高的是反向重复(IR)区(43.85-44.15%),其次是大型单拷贝（LSC）区域（36.25-36.65％）和小型单拷贝（SSC）区域（32.21-32.46％）。有33个高频密码子,以A/U结尾的占90.91%。总共鉴定出350个简单序列重复(SSR),单核苷酸重复是最常见的(61.43%)。总共鉴定了228个正向和141个回文重复。没有检测到反向或互补重复。所有序列的序列同一性都非常相似，特别是关于蛋白质编码和反向重复区。检测到七个高度可变区，可用于分子标记开发。构建的系统发育树表明Bromus是与小麦密切相关的单系分类群。这种对Bromus叶绿体基因组的比较分析为物种鉴定和系统发育研究提供了科学依据。
