Complete chloroplast genomes of two Ainsliaea species and the phylogenetic analysis in the tribe Pertyeae.

The genus Ainsliaea DC. is one of the major groups within the tribe Pertyeae (Asteraceae). It comprises several important Chinese medicinal species. However, the phylogenetic position has undergone a long process of exploration. The complete chloroplast (cp) genome sequences data has not been employed in species identification and phylogeny of Ainsliaea. In this study, the complete cp genomes of two Ainsliaea species (A. gracilis and A. henryi) were reported, followed by structural, comparative, and phylogenetic analyses within the tribe Peryteae. Both cp genomes displayed a typical quadripartite circular structure, with the LSC and SSC regions separated by the IR regions. The genomes were 152,959 (A. gracilis) and 152,805 (A. henryi) base pairs (bp) long, with a GC content of 37.6%. They were highly conserved, containing 134 genes, including 87 protein-coding genes, 37 tRNA genes, 8 rRNA genes, and 2 pseudogenes (rps19 and ycf1). Moreover, thirteen highly polymorphic regions (e.g., trnK-UUU, trnG-UCC, trnT-GGU, accD-psaI, and rpl22-rps19) were identified, indicating their potential as DNA barcodes. The phylogenetic analysis confirmed the placement of Ainsliaea in the tribe Pertyeae, revealing close relationships with the genera Myripnois and Pertya. In comparison with Ainsliaea, Myripnois was more closely related to Pertya. This study lays a theoretical foundation for future research on species identification, population genetics, resource conservation, and sustainable utilization within Ainsliaea and Pertyeae.

Comparative analysis of complete chloroplast genomes of Synotis species (Asteraceae, Senecioneae) for identification and phylogenetic analysis.

BACKGROUND: The Synotis (C. B. Clarke) C. Jeffrey & Y. L. Chen is an ecologically important genus of the tribe Senecioneae, family Asteraceae. Because most species of the genus bear similar morphology, traditional morphological identification methods are very difficult to discriminate them. Therefore, it is essential to develop a reliable and effective identification method for Synotis species. In this study, the complete chloroplast (cp.) genomes of four Synotis species, S. cavaleriei (H.Lév.) C. Jeffrey & Y.L. Chen, S. duclouxii (Dunn) C. Jeffrey & Y.L. Chen, S. nagensium (C.B. Clarke) C. Jeffrey & Y.L. Chen and S. erythropappa (Bureau & Franch.) C. Jeffrey & Y. L. Chen had been sequenced using next-generation sequencing technology and reported here. RESULTS: These four cp. genomes exhibited a typical quadripartite structure and contained the large single-copy regions (LSC, 83,288 to 83,399 bp), the small single-copy regions (SSC, 18,262 to 18,287 bp), and the inverted repeat regions (IR, 24,837 to 24,842 bp). Each of the four cp. genomes encoded 134 genes, including 87 protein-coding genes, 37 tRNA genes, 8 rRNA genes, and 2 pseudogenes (ycf1 and rps19). The highly variable regions (trnC-GCA-petN, ccsA-psaC, trnE-UUC-rpoB, ycf1, ccsA and petN) may be used as potential molecular barcodes. The complete cp. genomes sequence of Synotis could be used as the potentially effective super-barcode to accurately identify Synotis species. Phylogenetic analysis demonstrated that the four Synotis species were clustered into a monophyletic group, and they were closed to the Senecio, Crassocephalum and Dendrosenecio in tribe Senecioneae. CONCLUSIONS: This study will be useful for further species identification, evolution, genetic diversity and phylogenetic studies within this genus Synotis and the tribe Senecioneae.

Characterization and phylogenetic analysis of the complete chloroplast genome of Carpesium lipskyi (Asteraceae, Inuleae).

The species of Carpesium lipskyi C.Winkl. 1998 is an important traditional Chinese medicine in China. In this study, the complete chloroplast (cp) genome of C. lipskyi was determined and analyzed. The result showed that the complete cp genome of C. lipskyi was 151,244 bp in length, consisting of a large single-copy (LSC) region of 82,908 bp, a small single-copy (SSC) region of 18,430 bp, and a pair of inverted repeats (IRs) of 24,953 bp. The overall GC content of the C. lipskyi is 37.68%. The species of C. lipskyi possessed 127 genes, including 83 protein-coding genes, 36 transfer RNA genes, and eight ribosomal RNA genes. The present study found that Inula is sister groups with the closest genetic relationship. The obtained knowledge could provide useful information for future phylogenetic, taxonomic, and evolutionary studies on Inuleae.

Insights into comparative genomics, structural features, and phylogenetic relationship of species from Eurasian Aster and its related genera (Asteraceae: Astereae) based on complete chloroplast genome.

Aster L. is an economically and phylogenetically important genus in the tribe Astereae. Here, the complete plastomes of the eight Aster species were assembled and characterized using next-generation sequencing datasets. The results indicated the complete plastomes of Aster had a quadripartite structure. These genomes were 152,045-152,729 bp in length and contained 132-133 genes, including 87 protein-coding genes, 37-38 tRNA genes, and eight rRNA genes. Expansion or contraction of inverted repeat regions and forward, palindromic, complement, and reverse repeats were detected in the eight Aster species. Additionally, our analyses showed the richest type of simple sequence repeats was A/T mononucleotides, and 14 highly variable regions were discovered by analyzing the border regions, sequence divergence, and hotspots. Phylogenetic analyses indicated that 27 species in Astereae were clustered into six clades, i.e., A to D, North American, and outgroup clades, and supported that the genera Heteropappus, Kalimeris, and Heteroplexis are nested within Aster. The results indicated the clades B to D might be considered as genera. Divergence time estimate showed the clades A, B, C, and D diverged at 23.15 Mya, 15.13 Mya, 24.29 Mya, and 21.66 Mya, respectively. These results shed light on the phylogenetic relationships of Aster and provided new information on species identification of Aster and its related genera.

A new species, Aster yaoshanensis (Asteracae, Astereae), from Guangxi (China), based on morphology and molecular phylogenetic data.

Aster yaoshanensis sp. nov., a new species of the family Asteraceae is here described and illustrated. The species is presently known only from rock crevices of mountain valleys in Dayaoshan National Nature Reserve, Guangxi autonomous region, China. Phylogenetic analyses based on ITS sequences and complete plastome data have shown that this new species is a member of genus Aster with high support. Morphologically, it mostly resembles A. jishouensis, but it can be easily distinguished from the latter by bract indumentum (glabrous except margin ciliate vs. villous especially on veins abaxially, glabrous adaxially) and color (green vs. purple), shorter corolla (3.2-3.5 mm vs. 4.5-5.3 mm), bract stalk (obvious, ca.1.2 mm vs. sessile), and different distribution (Guangxi vs. Hunan). The detailed description, distribution map, and photos are provided. This study further elucidates the species identification, phylogeny and characteristic evolution of Aster.

Characterization and phylogenetic analysis of the chloroplast genome of Duhaldea cappa (Buch.-Ham. ex D.Don) Pruski & Anderb. (Asteraceae).

Duhaldea cappa, a valuable medicinal plant of genus Duhaldea in the tribe Inuleae, is predominantly found in China, Bhutan, India, Malaysia, Nepal, Pakistan, Thailand, and Vietnam. However, the genomic studies of Duhaldea cappa are limited. In this study, we successfully sequenced and assembled the complete chloroplast genome of Duhaldea cappa. The chloroplast genome is 150,819 bp in length with a 37.73% GC content. The chloroplast genome has a quadripartite structure, consisting of a large single-copy region of 82,731 bp, a small single-copy region of 18,168 bp, and a pair of inverted repeat sequences of 24,960 bp. The genome contains 133 genes. Among these genes, there are 88 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The phylogeny reconstructed from data of the complete chloroplast genome indicated that Duhaldea cappa is closely related to Pluchea indica in the tribe Inuleae. Analyzing and reporting the chloroplast genome of Duhaldea cappa will establish a solid theoretical and data foundation for the efficient development, conservation, and utilization of this plant species.

Characterization of the complete chloroplast genome sequence of Chinese endemic species of Nouelia insignis (Hyalideae, Asteraceae) and its phylogenetic implications.

This study was the first report complete chloroplast genome of Nouelia insignis (Asteraceae, Hyalideae), the large shrubs to small trees endemic to China. The circular whole cp genome of N. insignis was 151,524 bp in length, containing a large single-copy (LSC) region of 83,145 bp and a small single-copy (SSC) region of 18,261 bp. These two regions were separated by a pair of inverted repeat regions (IRa and IRb), each of them 25,060 bp in length. A total of 135 functional genes were encoded, consisting of 89 protein-coding genes, 38 tRNA genes, and eight rRNA genes. The overall GC content of the chloroplast genome sequence was 37.8%, and the GC contents of the LSC, SSC, and IR regions were 35.9, 31.5, and 43.2%, respectively. The phylogenetic analysis by the Bayesian analysis showed that the species of N. insignis was sister group with Gerbera jamesonii by strong support values, and thus was closely related to members of subfamilies of Cichorioideae and Pertyoideae. These results will be useful for the future studies of Asteraceae in the worldwide.