慈竹叶绿体基因组特征及系统发育分析OA

[Objective]This study aimed to characterize the structural features of the Bambusa emeiensis chloroplast genome and clarify its phylogenetic relationships.[Method]High-throughput sequencing technology was used for sequencing,assembly and gene annotatation of the B.emeiensis chloroplast ge-nome.Bioinformatic approaches were further applied to analyze its functional characteristics,repetitive sequences,codon usage bias,nucleotide diversity,and phylogenetic relationships.[Result]The chloro-plast genome of B.emeiensis exhibited a typical quadripartite structure with a total length of 139 451 bp,consisting of a large single-copy(LSC)region of 82 970 bp,a small single-copy(SSC)region of 12 881 bp,and two inverted repeat(IR)regions of 21 800 bp each.The overall GC content was 38.9%.A total of 132 coding genes were annotated,including 85 protein-coding genes,39 tRNA genes and 8 rRNA genes.Fifty-four interspersed repeat sequences and 48 simple sequence repeat(SSR)loci were identi-fied.Synonymous codons ending with A/U were preferred,while codons ending with G/C were less fre-quently utilized.The IR/SC boundaries of Bambusa species were relatively conserved.Nucleotide diver-sity was higher in non-coding regions than in coding regions,and three highly variable hotspot regions were identified:trnG-UCC_1-trnT-GGU,rpl36-inf A,and ndhD-psaC.[Conclusion]Phylogenetic analysis based on chloroplast genomes of 20 plant species including B.emeiensis revealed that B.emeien-sis clustered within the same clade as other Bambusa species.These results provide a theoretical basis for studies on the genetic background,adaptive evolution and phylogeny of B.emeiensis.