禾本科大油芒属5个叶绿体基因组比较分析OA

The classification status of Spodiopogon in the family Poaceae is unclear.We aimed to provide novel insights into the chloroplast genome characteristics and phylogenetic relationships of Spodiopogon by sequencing,assembling,annotating,and analyzing structural features of the chloroplast genomes of five closely related species:S.sagittifolius,S.cotulifer,S.sibiricus,S.duclouxii,and S.formosanus.Analysis revealed that all five chloroplasts possessed a typical quadripartite structure,with a consistent number of protein-coding genes,tRNAs,and rRNAs.Although slight variations were observed in the inverted repeat(IR)/large single-copy(LSC)boundaries,the overall structure was highly conserved.The LSC and small single-copy regions exhibited greater divergence than the IR region.Codon usage bias was observed across all species,with minimal interspecies variation.Phylogenetic analysis supported the monophyly of Spodiopogon with two clustered clades,in which the clade of S.cotulifer,S.sibiricus,and S.formosanus was reciprocally sister to that of S.sagittifolius and S.duclouxii.These findings are instrumental in investigating the molecular taxonomy and evolutionary history of Spodiopogon.