ABSTRACT
Calendula officinalis L.is a versatile medicinal plant with numerous applications in various fields. However, its chloroplast genome structure, features, phylogeny, and patterns of evolution and mutation remain largely unexplored. This study examines the chloroplast genome, phylogeny, codon usage bias, and divergence time of C. officinalis, enhancing our understanding of its evolution and adaptation. The chloroplast genome of C. officinalis is a 150,465 bp circular molecule with a G + C content of 37.75% and comprises 131 genes. Phylogenetic analysis revealed a close relationship between C. officinalis, C. arvensis, and Osteospermum ecklonis. A key finding is the similarity in codon usage bias among these species, which, coupled with the divergence time analysis, supports their close phylogenetic proximity. This similarity in codon preference and divergence times underscores a parallel evolutionary adaptation journey for these species, highlighting the intricate interplay between genetic evolution and environmental adaptation in the Asteraceae family. Moreover unique evolutionary features in C. officinalis, possibly associated with certain genes were identified, laying a foundation for future research into the genetic diversity and medicinal value of C. officinalis.
Subject(s)
Calendula , Evolution, Molecular , Genome, Chloroplast , Phylogeny , Plants, Medicinal , Plants, Medicinal/genetics , Calendula/genetics , Codon Usage , Base Composition , Chloroplasts/geneticsABSTRACT
Sedum bulbiferum is a traditional medicinal plant in China, with few reports on its chloroplast genome. In this study, the chloroplast genome of Sedum bulbiferum was characterized, and its phylogenetic position among other closely related species was studied. The results showed that the full length of the chloroplast genome was 150,074 bp, containing a large single-copy (LSC) region and a small single-copy (SSC) region of 81,730 and 16,726 bp, respectively, as well as two inverted repeat regions (IRs) of 25,809 bp like other plants. A total of 128 genes were found, including 83 protein-coding genes, 37 tRNA genes, and eight rRNA genes. Phylogenetic analysis showed that Sedum bulbiferum is closely related to Sedum emarginatum, Sedum alfredii, Sedum tricarpum, Sedum plumbizincicola, and Sedum sarmentosum.
ABSTRACT
Galium spurium is a farmland weed, with strong stress resistance. However, its chloroplast genome has never been reported. In this study, the complete sequence of the chloroplast genome of G. spurium was characterized, which is a circular molecule, 153,481 bp in length, and with a large single copy region of 84,334 bp, a small single copy region of 17,057 bp, and a pair of inverted repeat regions of 26,045 bp. The whole genome contained 127 genes, including 82 protein-coding genes, 37 transfer RNA genes, and eight ribosomal RNA genes. Phylogenetic analysis shows that it relates closely to G. aparine. This study provides a basis for the further phylogenic study of Galium.
ABSTRACT
Centaurea cyanus has been a weed in farmland for a long time. In this study, the chloroplast genome of C. cyanus was sequenced to establish the phylogenetic relationship between its genomic characteristics and other related species. The chloroplast gene structure of C. cyanus is a circular molecule with a length of 152,433 bp, including a large single-copy (LSC) region of 83,464 bp, a small single-copy (SSC) region of 18,545 bp, and a pair of inverted repeats sequences (IRs) region of 25,212 bp. The whole genome contains 130 genes, including 86 protein-coding genes, 36 tRNA genes, and eight rRNA genes. Phylogenetic analysis showed that C. cyanus is close to Carthamus. tinctorius, C. tinctorius, C. diffusa, and C. maculosa, and all of them were in one clade. This study provides genetic resource information for the further study of Centaurea.
ABSTRACT
Compared with the classical Kendall's model to analyze the steady-state peeling behavior of an infinite length film attaching to a rigid substrate, this paper establishes a model of a finite length thin film adhering on a rigid substrate and analyzes the influence of film's initial adhesion length, film stiffness, and initial cantilever length of films on the whole interface peeling behavior. Both theoretical prediction and finite element calculation are carried out. The typical relationship between the peeling force and the separation distance at the loading point is obtained as well as the morphology of deformed films. It is found that the initial adhesion length has a significant effect on the peeling behavior. Differently from the case of infinite thin films, whether the steady-state peeling process can be achieved or not depends on the film's adhesion length. If the film is long enough, the whole peeling process can be divided into an initial peeling stage, a transition stage, a steady-state stage, and an unstable peeling stage. The maximum peeling force of the interface does not necessarily occur in the steady-state stage, which is influenced by the film's initial adhesion length, film stiffness, and initial cantilever length. The results achieved in this paper can not only provide a systematic understanding of peeling behavior of a thin film on a rigid substrate, but also be helpful for the design of high-quality interface and peeling tests in practical applications.