播娘蒿叶绿体基因组特征与系统发育研究OA

The complete genome information of the chloroplast of the medicinal plant Descurainia so-phia was investigated.The structure,sequence characteristics and phylogenetic relationship of the chloroplast were analyzed to provide reference for its molecular identification and genetic diversity re-search,germplasm resource conservation and development and utilization.The genome was sequenced using the Illumina Novaseq 6000 platform and the structural characteristics,sequence characteristics,codon preference and phylogeny of the genome were analyzed by combining bioinformatics software.The results showed that the complete chloroplast genome of Descurainia sophia was 153 976 bp in length,with the lengths of the reverse repeat sequences IRa and IRb both being 26 268 bp.The lengths of the large single-copy region LSC and the small single-copy region SSC were 83 870 bp and 17 570 bp respectively.The total GC content was 36.48％and there were 132 coding genes,including 87 protein-coding genes,37 tRNA genes and 8 rRNA genes.The structure of the chloroplast genome of Descurainia sophia was highly similar to that of other species in the Brassicaceae family,without obvious boundary contraction or expansion.A total of 73 SSR loci were detected in the chloroplast ge-nome of Descurainia sophia,with the A/T dinucleotide repeat being the most frequent.The codon preference ended with A/T.The phylogeny of Descurainia sophia was clustered together with De-scurainia erodiifolia(with a bootstrap value of 100％).The structural characteristics of the chloro-plast genome of Descurainia sophia were conserved,but there were differences in codon preference,genome boundaries and nucleotide polymorphism compared with the Brassicaceae plants.Descurainia sophia had the closest genetic relationship with Descurainia.