Abstract: Cortiella is a small genus of the tribe Selineae （Apiaceae）, yet its plastome characteristics and phylogenetic position within the tribe remain unclear. In this study, we analyzed the previously sequenced plastome of C. hookeri using Geneious, codonW, and MISA software. Furthermore, we performed maximum likelihood and Bayesian inference analyses based on plastome data, with expanded taxon sampling covering approximately 51% of genera in Selineae. The results showed that the C. hookeri plastome exhibited a typical quadripartite circular structure, encoding 113 unique genes, with a preferred usage of A/U-ending codons. The simple sequence repeats of plastome were mainly composed of A/T and mostly located in the large single copy region. These features were consistent with those of other members of Selineae, indicating Cortiella plastome was highly conserved. Nevertheless, the plastome size was varied across genera within the tribe, which may be mainly attributed to the expansion of the inverted repeat regions. Moreover, the maximum likelihood and Bayesian trees reconstructed from the 79 shared protein coding regions of plastome displayed identical topologies and clarified the phylogenetic position of Cortiella within Selineae with high support values. This study enriches the genetic resources of Cortiella and lays a foundation for future phylogenetic and taxonomic research on this genus.

Key words: Apiaceae, Cortiella, plastome, phylogeny