ABSTRACT
Lysimachia christinae Hance is widely distributed in subtropical China at the elevational range from 500-2300 m. The species is an important medicinal herb for treating jaundice, urinary disorders, and the liver. Here, we sequenced and characterized the whole plastid genome of L. christinae. It is 154,810 bp in length, containing two copies of inverted repeat (IR) regions (26,034 bp, each), a large single-copy (LSC) region (84,809 bp), and a small single-copy (SSC) region (17,933 bp). It has 114 genes, of which 80 are protein-coding, 30 are tRNA, and 4 are rRNA genes. The ML tree indicates L. christinae is closely related to Lysimachia congestiflora Hemsl. This genome information can help us better construct a backbone phylogeny of Lysimachia in the future.
ABSTRACT
The herb Isodon serra (Maximowicz) Kudô, which is widely distributed in China and its neighbor regions, is a well-known traditional Chinese medicinal plant. In this study, we characterized the complete plastid genome sequence of I. serra using Illumina sequencing data. The plastome is 152,676 bp in length and contains a typical quadripartite structure. The inverted repeat (IR), large-single copy (LSC) and small-single copy (SSC) regions each has 25,716 bp, 83,564 bp, and 17,680 bp. The genome contains 80 protein coding genes (PCGs), 30 transfer RNAs (tRNA), and four ribosomal RNAs (rRNA). The phylogenetic result indicates I. serra together with genera Ocimum and Lavandula formed tribe Ocimeae clade.
ABSTRACT
DNA barcoding of plants poses particular challenges, especially in differentiating, recently diverged taxa. The genus Gentiana (Gentianaceae) is a species-rich plant group which rapidly radiated in the Himalaya-Hengduan Mountains in China. In this study, we tested the core plant barcode (rbcL + matK) and three promising complementary barcodes (trnH-psbA, ITS and ITS2) in 30 Gentiana species across 6 sections using three methods (the genetic distance-based method, Best Close Match and tree-based method). rbcL had the highest PCR efficiency and sequencing success (100%), while the lowest sequence recoverability was from ITS (68.35%). The presence of indels and inversions in trnH-psbA in Gentiana led to difficulties in sequence alignment. When using a single region for analysis, ITS exhibited the highest discriminatory power (60%-74.42%). Of the combinations, matK + ITS provided the highest discrimination success (71.43%-88.24%) and is recommended as the DNA barcode for the genus Gentiana. DNA barcoding proved effective in assigning most species to sections, though it performed poorly in some closely related species in sect. Cruciata because of hybridization events. Our analysis suggests that the status of G. pseudosquarrosa needs to be studied further. The utility of DNA barcoding was also verified in authenticating 'Qin-Jiao' Gentiana medicinal plants (G. macrophylla, G. crassicaulis, G. straminea, and G. dahurica), which can help ensure safe and correct usage of these well-known Chinese traditional medicinal herbs.