Abstract:
Tanacetum cinerariifolium is the sole insecticidal horticultural crop cultivated commercially worldwide due to its high commercial value of natural pyrethrins extracted from flower heads, widely used in organic agriculture and household pest control. In this study, the chloroplast genome of T. cinerariifolium was sequenced using the Illumina HiSeq 2500 sequencing platform, and its structural features and systematic evolution were analyzed. The results showed that T. cinerariifolium has a typical chloroplast quadripartite structure with a genome size of 150 171 bp, including 84 protein-coding genes, 37 transfer RNA genes and 8 ribosomal RNA genes. Codon preference analysis revealed an A/U-bias at the third codon position in its chloroplast genome, with the codon for leucine being the most frequently used. A total of 41 simple sequence repeat(SSR) loci were identified in its chloroplast genome, including 37 single nucleotide repeats and 4 compound nucleotide repeats. Based on a phylogenetic tree constructed from the chloroplast genome sequences of 39 Asteraceae species, the chloroplast genome of T. cinerariifolium was highly conserved, and it showed a close relationship with Ismelia carinata, except for its closely related Tanacetum coccineum. These findings could provide a basis for developing molecular markers, genetic diversity, and further studies on the conservation biology and population genetics of Tanacetum.