The complete chloroplast genome of Ocimum americanum Linnaeus 1755 and phylogenetic analysis among the Lamiaceae family.

Ocimum americanum Linnaeus 1755 (Lemon basil) is an essential medicinal species in the Ocimum genus. Its leaf decoction is traditionally used to treat diabetes, constipation, diarrhea, piles, and dysentery. The essential oils from this species have intense fungicidal activity. The complete chloroplast genome sequence of O. americanum was assembled from Illumina paired-end sequencing data. The O. americanum chloroplast genome was 152,460 bp in length, containing a large single copy (LSC) region of 83,459 bp and a small single copy (SSC) region of 17,607 bp, separated by a pair of inverted repeats (IRs) of 25,697 bp. The genome contained 134 unique genes, including 89 protein-coding, 37 tRNA, and eight rRNA genes. Among them, nine genes had a single intron, and two genes contained two introns. The overall GC content of the chloroplast genome was 38%, while the corresponding values of LSC, SSC, and IR regions were 35.8%, 31.7%, and 43.1%, respectively. In the phylogenetic analysis, all the Ocimum species formed a group closely related to Plectranthus barbatus. O. americanum was more closely related to O. gratissimum and O. basilicum than the other species of Ocimum included in this study.