Background: Baitouweng is a traditional Chinese medicine with a long history of different applications. Although referred to as a single medicine, Baitouweng is actually comprised of many closely related species. It is therefore critically important to identify the different species that are utilized in these medicinal applications. Knowledge about their phylogenetic relationships can be derived from their chloroplast genomes and may provide additional insights into development of molecular markers. Methods: Genomic DNA was extracted from six species of Pulsatilla and then sequenced on an Illumina HiSeq 4000. Sequences were assembled into contigs by SOAPdenovo 2.04, aligned to the reference genome using BLAST, and then manually corrected. Genome annotation was performed by the online DOGMA tool. General characteristics of the cp genomes of the six species were analyzed and compared with closely related species. Additionally, phylogenetic trees were constructed, based on single nucleotide polymorphisms (SNPs) and 51 shared protein-coding gene sequences in the cp genome among all 31 species via maximum likelihood. Results: The size of cp genomes of P. chinensis (Bge.) Regel, P. chinensis (Bge.) Regel var. kissii (Mandl) S. H. Li et Y. H. Huang, P. cernua (Thunb.) Bercht. et Opiz f. plumbea J. X. Ji et Y. T. zhao, P. dahurica (Fisch.) Spreng, P. turczaninovii Kryl. et Serg, and P. cernua (Thunb.) Bercht. et Opiz. were 163,851 bp, 163,756 bp, 162,481 bp, 162,450 bp, 162,795 bp, and 162,924 bp, respectively. Each species included two inverted repeat regions, a small single-copy region, and a large single-copy region. A total of 134 genes were annotated, including 90 protein-coding genes, 36 tRNAs, and eight rRNAs across all species. In simple sequence repeat analysis, only P. dahurica was found to contain hexanucleotide repeats. A total of 26, 39, 32, 37, 32 and 43 large repeat sequences were identified in the genic regions of the six Pulsatilla species. Nucleotide diversity analysis revealed that the rpl36 gene and ccsA-ndhD region have the highest Pi value. In addition, two phylogenetic trees of the cp genomes were constructed, which laced all Pulsatilla species into one branch within Ranunculaceae. Conclusions: We identified and analyzed the cp genome features of six species of P. Miller, with implications for species identification and phylogenetic analysis.

Background: Burdock is a biennial herb of Asteraceae found in Northern Europe, Eurasia, Siberia, and China. Its mature dry fruits, called Niu Bang Zi, are recorded in various traditional Chinese medicine books. With the development of sequencing technology, the mitochondrial, chloroplast, and nuclear genomes, transcriptome, and sequence-related amplified polymorphism (SRAP) fingerprints of burdock have all been reported. To make better use of this data for further research and analysis, a burdock database was constructed. Results: This burdock multi-omics database contains two burdock genome datasets, two transcriptome datasets, eight burdock chloroplast genomes, one burdock mitochondrial genome, one A. tomentosum chloroplast genome, one A. tomentosum mitochondrial genome, 26 phenotypes of burdock varieties, burdock rhizosphere-associated microorganisms, and chemical constituents of burdock fruit, pericarp, and kernel at different growth stages (using UPLC-Q-TOF–MS). The wild and cultivation distribution of burdock in China was summarized, and the main active components and pharmacological effects of burdock currently reported were concluded. The database contains ten central functional modules: Home, Genome, Transcriptome, Jbrowse, Search, Tools, SRAP fingerprints, Associated microorganisms, Chemical, and Publications. Among these, the “Tools” module can be used to perform sequence homology alignment (Blast), multiple sequence alignment analysis (Muscle), homologous protein prediction (Genewise), primer design (Primer), large-scale genome analysis (Lastz), and GO and KEGG enrichment analyses (GO Enrichment and KEGG Enrichment). Conclusions: The database URL is http://210.22.121.250:41352/. This burdock database integrates molecular and chemical data to provide a comprehensive information and analysis platform for interested researchers and can be of immense help to the cultivation, breeding, and molecular pharmacognosy research of burdock.

Introduction: Blechnopsis orientalis (L.) C. Presl is a medicinal and edible fern species belonging to the Blechnaceae family. Currently, the complete mitochondrial genome of B. orientalis, as well as those of other Blechnaceae species, remains unreported, and studies on fern mitochondrial genome are limited.Methods: In this study, the B. orientalis mitochondrial genome was sequenced using both Nanopore PromethION and Illumina NovaSeq 6000 platforms. Genome annotation was performed using MITOFY and MFANNOT, with structural visualization via OGDRAW. In-depth analyses were conducted, including assessments of non-synonymous/synonymous mutation ratios (Ka/Ks), codon usage bias, repeat sequence identification, RNA editing site prediction, collinearity, and the identification of homologous fragments between chloroplast and mitochondrial genomes. Finally, we employed both the maximum likelihood (ML) and Bayesian (BI) methods to analyze the phylogenetic relationships among B. orientalis and nine other fern and lycophyte species.Results: The mitochondrial genome of B. orientalis has a complex structure comprising 80 contigs, with a total length of 501,663 bp and a GC content of 48.53%. A total of 179 genes were identified, including 40 protein-coding genes (PCGs), 98 tRNA genes, 40 rRNA genes, and one pseudogene (rps11). Phylogenetic analysis based on PCGs from both chloroplast genome and mitochondrial genome aligned with the relationships described in the Pteridophyte Phylogeny Group I (PPG I) system. Further comparison with mitochondrial genome of ten other reported fern and lycophyte species revealed that the mitochondrial genome PCGs in these plants are highly conserved, despite significant genome rearrangements among mitochondrial genome.Discussion: The findings of this study provide valuable insights into the evolutionary analysis of B. orientalis and contribute to understanding the characteristics and evolutionary relationships of mitochondrial genome in ferns and lycophytes.

Background: Pulsatilla saxatilis, a new species of the genus Pulsatilla has been discovered. The morphological information of this species has been well described, but its chloroplast genome characteristics and comparison with species of the same genus remain to be reported. Results: Our results showed that the total length of chloroplast (cp.) genome of P. saxatilis is 162,659 bp, with a GC content of 37.5%. The cp. genome contains 134 genes, including 90 known protein-coding genes, 36 tRNA genes, and 8 rRNA genes. P. saxatilis demonstrated similar characteristics to other species of genus Pulsatilla. Herein, we compared cp. genomes of 10 species, including P. saxatilis, and found that the cp. genomes of the genus Pulsatilla are extremely similar, with a length of 162,322–163,851 bp. Furthermore, The SSRs of Pulsatilla ranged from 10 to 22 bp in length. Among the four structural regions of the cp. genome, most long repeats and SSRs were detected in the LSC region, followed by that in the SSC region, and least in IRA/ IRB regions. The most common types of long repeats were forward and palindromic repeats, followed by reverse repeats, and only a few complementary repeats were found in 10 cp. genomes. We also analyzed nucleotide diversity and identified ccsA_ndhD, rps16_trnK-UUU, ccsA, and rbcL, which could be used as potential molecular markers for identification of Pulsatilla species. The results of the phylogenetic tree constructed by connecting the sequences of high variation regions were consistent with those of the cp. gene phylogenetic tree, and the species more closely related to P. saxatilis was identified as the P. campanella. Conclusion: It was determined that the closest species to P. saxatilis is P. campanella, which is the same as the conclusion based on pollen grain characteristics, but different from the P. chinensis determined based on morphological characteristics. By revealing information on the chloroplast characteristics, development, and evolution of the cp. genome and the potential molecular markers, this study provides effective molecular data regarding the evolution, genetic diversity, and species identification of the genus Pulsatilla.