Characterization of the Four L. Species from Kazakhstan Based on Complete Plastomes and Nuclear Ribosomal Internal Transcribed Spacer () Sequences.

BACKGROUND

L. is an economically significant genus with species that are notable for their rich content of phenolic compounds. Despite its importance, the taxonomy of remains complex and unresolved.

METHODS

We sequenced, assembled, and performed comparative analyses of the complete plastomes of four species: , , , and . In addition to the plastome, we sequenced the nuclear ribosomal internal transcribed spacer ().

RESULTS

Plastomes ranged in size from 157,148 bp () to 157,346 bp (). In each plastome, 136 genes were annotated, comprising 90 protein-coding, 38 tRNA, and eight rRNA genes. A total of 905 SSRs were identified, ranging from 224 () to 229 in . Nine highly variable regions were detected, including two coding genes ( and ) and seven intergenic spacers ((), ()(), , (), (), ()(), and ). Maximum Likelihood (ML) phylogenetic analyses based on the complete plastome and gene datasets consistently resolved the species into three major clades, with strong bootstrap support. In contrast, the ML tree based on resolved species into four clades but showed lower bootstrap values, indicating reduced resolution compared to plastid datasets.

CONCLUSIONS

Our findings underscore the value of plastome data in resolving phylogenetic relationships within the genus .