Characterization of the complete chloroplast genome of Corydalis inopinata Prain ex Fedde (Papaveraceae)

Abstract The complete chloroplast genome of Corydalis inopinata Prain ex Fedde was assembled and characterized in this study. The chloroplast genome was 181,335 bp in length, consisting of a large single-copy (LSC) region of 91,727 bp, a small single-copy (SSC) region of 1502 bp, and a pair of inverted repeat (IR) regions of 44,053 bp. It encoded 110 unique genes, including 68 protein-coding genes, 29 tRNA genes, 4 rRNA genes, and 9 pseudogenes. Phylogenetic analyses by maximum likelihood (ML) and Bayesian inference (BI) revealed that C. inopinata was closely related to C. conspersa Maxim. with full support in the present sampling. The complete plastid genome provided in this work would be useful for elucidating the taxonomy, phylogeny, and evolution of C. inopinata and other related species.

Corydalis DC., one of the largest genus in Chinese flora, stands out for its complex, variable, interconnected and intergrading morphological characters (Wu et al. 1996). To date, relatively few molecular researches have been done on this taxon, leaving us with many unresolved questions about its taxonomy, phylogeny, and evolution. In the present study, we characterized and reported the complete plastid genome of C. inopinata Prain ex Fedde, a cushion-like alpine perennial herb, and investigated its phylogeny within Ranunculales.
The complete chloroplast genome of C. inopinata was 1,81,335 bp in length, exhibiting typical angiosperm quadripartite structure. The large single-copy (LSC), inverted repeat (IR), and small single-copy (SSC) were 91,727 bp, 44,053 bp, and 1,502 bp, respectively. Inversion and translocation of about 5 kb (rbcL, atpB, atpE, and trnM-CAU) was observed in the LSC. The IRs expanded markedly into the SSC, resulting in the IRs 15 kb longer than the average. In total, 110 genes were predicted, including 68 protein-coding genes, 29 tRNA genes, four rRNA genes, and nine pseudogenes (eight ndh gene and trnV-UAC). Three genes (accD, ndhJ, and ndhI) were absent in this chloroplast genome. Twenty-four genes were duplicated in the IR, including eight protein-coding genes, four rRNA genes, eight tRNA genes, and four pseudogenized ndh genes. The GC content of the complete chloroplast genome, LSC, IR, and SSC regions were 40.93%, 39.85%, 42.17%, and 34.38%, respectively. The ML and BI analyses both revealed that C. inopinata belonged to Fumarioideae (Papaveraceae) clade, and C. inopinata was closely related to C. conspersa Maxim. with full support in the present sampling ( Figure 1).
The complete plastid genome provided in this work would be useful for elucidating the taxonomy, phylogeny, and evolution of C. inopinata, and providing molecular data for future research in Corydalis as well.

Disclosure statement
No potential conflict of interest was reported by the author(s).

Funding
The work was supported by Grants from the National Natural Science Data availability statement