RESUMEN
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.
RESUMEN
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.
RESUMEN
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.
RESUMEN
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.