Mitochondrial genome and phylogenetic analysis of Aster Indicus L.

Aster indicus L. is a medicinally important species with therapeutic value from its entire plant. However, genomic research, particularly concerning the mitochondrial genome, remains sparse. This study sequenced the mitochondrial genome of A. indicus, revealing a length of 224,973 bp with an A/T content of 54.5%. The mitogenome encodes 54 protein-coding genes, 21 tRNAs, and 3 rRNAs. Identification of genomic features included 20 simple sequence repeats, 143 dispersed repeats, 15 tandem repeats, and 10 segments derived from chloroplast DNA. Analysis of codon usage indicated a preference for A/U-terminating codons. Comparative synteny analysis with 11 species in Asteraceae showed a 94.77% sequence identity with Aster batangensis Bureau & Franch., accompanied by extensive genomic rearrangements. Most protein-coding genes exhibited evidence of purifying selection, with the exception of nad1. Phylogenetically, A. indicus is closest to A. batangensis; as expected, the genus Aster is genetically closer to the genus Erigeron, in agreement with their placement in tribe Astereae, but distant from Arctium and Carthamus, that belongs to tribe Cardueae. This study delineates the structural characteristics and sequence features of the A. indicus mitochondrial genome and enriches the genetic resources of the genus Aster and Asteraceae family, and establishing a foundational basis for future functional, evolutionary, and pharmacological investigations of this therapeutically significant species.