Complete Chloroplast Genome Research Articles

Comparative and evolutionary analysis of chloroplast genomes from five rare Styrax species

BackgroundStyrax, a vital raw material for shipbuilding, construction, perfumes, and drugs, represents the largest and most diverse genus in the Styracaceae. However, there is a relative scarcity of research on Styrax, particularly in evolution and genetics. Therefore, this study conducted comparative and evolutionary analyses of the chloroplast genomes of five rare Styrax species (S. argentifolius, S. buchananii, S. chrysocarpus, S. finlaysonianus, and S. rhytidocarpus).ResultsThe results indicated that, despite high levels of conservation in chloroplast genome structure among these species, specific mutation hotspot regions exist, particularly involving the expansion and contraction of the IR region. Additionally, evidence of positive selection was detected in eight genes (atpB, ccsA, ndhD, petA, rbcL, rpoC1, ycf1, and ycf2), which may be associated with adaptive evolution in response to environmental changes. Phylogenetic analysis revealed conflicts between trees constructed based on coding sequences and complete chloroplast genomes for several species, which were similar to previous phylogenetic studies.ConclusionThis study underscores the importance of increasing sample sizes to enhance the accuracy of phylogenetic analyses and provides a new perspective on understanding the adaptive evolution of Styrax species. These findings are not only important for the conservation and sustainable use of Styrax, but also provide valuable insights for research in plant evolution and ecology within the genus.

First Recorded Parasitism of Keteleeria evelyniana by Cuscuta chinensis in Yunnan, China.

The genus Cuscuta, also known as dodder, comprising numerous holoparasitic plant species, exhibits a broad distribution across China, where it is recognized for its detrimental effects on indigenous florae (Narukawa, et al, 2021). Within this genus, Cuscuta chinensis stands out as a species of particular concern due to its potential to imperil a diverse array of plant species (Tang, et al, 2024). Notably, there is a dearth of literature documenting its parasitic interactions with K. evelyniana, a conifer species that is both ecologically and economically significant (Tang, et al, 2024). The ecological services provided by this species, along with the high quality of its timber, highlight its importance in both ecological and economic contexts. In our 2023 field expeditions, we documented for the first time the parasitic interaction between C. chinensis and K. evelyniana in Kunming, Yunnan Province, China (102°46'12″, 25°05'23″). The K. evelyniana plants parasitized by C. chinensis showed symptoms including chlorosis, wilting, and defoliation. The specimens collected presented yellow, leafless, twining stems with haustoria at the nodes, characteristic of C. chinensis. The species possess an umbel inflorescence containing 2 to 10 white flowers, each with a subtle pentamerous corolla. Morphological assessment identified the specimen as C. chinensis. We surveyed a 2.8-hectares area around an infected K. evelyniana, examining approximately 20 plants, and found only one instance of C. chinensis infection. Given its rarity and the presence of C. chinensis on other species outside this area, we consider K. evelyniana a rare host for this dodder. To ascertain the species identity with greater certainty, we sequenced the complete chloroplast genome using Illumina sequencing technology. Total genomic DNA was extracted from specimen stems and subjected to whole-genome sequencing. The chloroplast genome was subsequently assembled and annotated using the PGA (Plant Genome Annotation) tool (Qu et al. 2019), resulting in a complete chloroplast genome sequence that was deposited in GenBank (Accession number: PQ585822). The chloroplast genome has a length of 86,800 bp. BLAST analysis confirmed the species of the Dodder as C. chinensis, as it exhibited a 99.85% similarity with the previously uploaded sequence (Accession number MH780079), with 100% query coverage. Phylogenetic analyses (maximum likelihood with 1,000 bootstrap replicates and Bayesian inference with 2,000,000 MCMC generations, sampling every 1,000 generations) confirmed the specimen as C. chinensis. Ultimately, the specimen of the dodder recovered in Yunnan Province was classified as C. chinensis, employing a holistic approach that considered morphological attributes, sequence homology, and phylogenetic affiliations. A voucher specimen of K. evelyniana, parasitized by C. chinensis, is archived in the herbarium of the College of Horticulture and Landscape, Yunnan Agricultural University (No. 20230011). To our knowledge, this represents the first report of C. chinensis parasitizing K. evelyniana in China. This novel finding presents unprecedented conservation challenges for the preservation of K. evelyniana, while simultaneously enhancing our understanding of the host range and ecological significance of Cuscuta species.

Comparative Chloroplast Genomics of Actinidia deliciosa Cultivars: Insights into Positive Selection and Population Evolution.

The chloroplast genome, as an important evolutionary marker, can provide a new breakthrough direction for the population evolution of plant species. Actinidia deliciosa represents one of the most economically significant and widely cultivated fruit species in the genus Actinidia. In this study, we sequenced and analyzed the complete chloroplast genomes of seven cultivars of Actinidia. deliciosa to detect the structural variation and population evolutionary characteristics. The total genome size ranged from 156,404 bp (A. deliciosa cv. Hayward) to 156,495 bp (A. deliciosa cv. Yate). A total of 321 simple sequence repeats (SSRs) and 1335 repetitive sequences were identified. Large-scale repeat sequences may facilitate indels and substitutions, molecular variations in A. deliciosa varieties' chloroplast genomes. Additionally, four polymorphic chloroplast DNA loci (atpF-atpH, atpH-atpI, atpB, and accD) were detected, which could potentially provide useful molecular genetic markers for further population genetics studies within A. deliciosa varieties. Site-specific selection analysis revealed that six genes (atpA, rps3, rps7, rpl22, rbcL, and ycf2) underwent protein sequence evolution. These genes may have played key roles in the adaptation of A. deliciosa to various environments. The population evolutionary analysis suggested that A. deliciosa cultivars were clustered into an individual evolutionary branch with moderate-to-high support values. These results provided a foundational genomic resource that will be a major contribution to future studies of population genetics, adaptive evolution, and genetic improvement in Actinidia.

The first complete chloroplast genome of Glycine tabacina (Fabaceae) and its phylogenetic analysis

The complete chloroplast genome of Glycine tabacina (Labill.) Benth., a perennial legume native to southern China and the Pacific islands, was sequenced for the first time. The circular genome spans 152,842 bp, comprising a large single-copy (83,882 bp), a small single-copy (17,872 bp), and two inverted repeats (25,544 bp). It contains 128 genes, including 83 protein-coding genes. Phylogenetic analysis within the Glycine genus revealed two clusters, with G. tabacina closely related to G. dolichocarpa. This high-quality genome provides a foundation for future phylogenetic and conservation studies of G. tabacina.

Characterization of the complete chloroplast genome of Brunfelsia brasiliensis (Spreng.) L.B.Sm. & Downs

Brunfelsia brasiliensis (B. brasiliensis) (Spreng.) L.B.Sm. & Downs is a perennial evergreen shrub that is widely cultivated as an ornamental plant in tropical and subtropical regions. This study presents the complete chloroplast genome of B. brasiliensis, having a length of 169,062 bp. The chloroplast genome contains 137 genes, including 92 protein-coding, 37 tRNA genes, and 8 rRNA genes. Phylogenetic analysis reveals that Petunia hybrida and P. exserta are closely linked to B. brasiliensis in evolutionary terms. This first chloroplast genome assembly is a valuable resource for future genetic and molecular biology studies of the genus Brunfelsia.

Original species identification of Epimedii Folium (Epimedium) and their distributional responses to climate change

Abstract Background Epimedii Folium is well known for its medicinal value. Four Epimedium species—Euphorbia brevicornu, E. sagittatum, E. pubescens, and E. koreanum—are the designated original plant s of Epimedii Folium. Objective The objective of this study is to facilitate the identification of the four Epimedium species and clarify their distributional responses to climate change. Methods In this study, we assessed the genetic divergence of the four species and identified the molecular markers for species identification by using chloroplast genome sequences. Furthermore, we forecasted the distribution of potentially suitable regions of the four species Folium under climate change. Results The authors obtained 26 chloroplast genome sequences of the four species and identified 1393 variable sites and 273 indel events. Genetic divergence analyses revealed that E. koreanum had long genetic distance from the other three species. Compared with the complete chloroplast genome, six hypervariable markers were discovered, and both rps4-trnL and ndhF were chosen as Epimedii Folium-specific DNA barcodes. Climate change is expected to influence the geographical distribution of the four Epimedium species, which were primarily found in China, South Korea, and Japan, leading to both expansion and contraction of their distribution ranges. Conclusions Two identification markers were selected as the specific DNA barcodes for all four original plant species of Epimedii Folium. In addition, the shift of potential suitable area in various climate scenarios has been predicted. With the support of identification markers and the dynamics of suitable distribution areas, we are able to establish a foundation for the sustainable utilization of medicinal Epimedium resources in the future.

Complete chloroplast genomes of 6 rare and endangered species of Epimedium (Berberidaceae) from China: Genomic features, comparative analysis, and phylogenetic relationship

Complete chloroplast genomes of 6 rare and endangered species of Epimedium (Berberidaceae) from China: Genomic features, comparative analysis, and phylogenetic relationship

There and back again: historical biogeography of neotropical magnolias based on high-throughput sequencing

BackgroundThe Neotropics are considered one of the most biodiverse areas in the world, housing at least one third of all vascular plant species. One of the genera that has diversified in the Neotropics is Magnolia, with about 174 species of three sections (Macrophylla, Magnolia and Talauma) endemic to the Americas. In this work, we study the biogeographic history of the Neotropical Magnolia species using high-throughput sequencing data. Sequences from 39 species (38 from Magnolia and one from the sister genus Liriodendron) were assembled. The dataset contained sequences from 239 nuclear targets and complete chloroplast genomes. Phylogenomic hypotheses and the ancestral distribution range of Magnolia were reconstructed.ResultsThe results of the calibrated phylogenetic hypotheses and ancestral range construction suggest that the earliest arrival in the Neotropics were the ancestors of section Talauma (38 million years ago), which colonized the Pacific region. This early presence in South America suggests long-distance, overwater dispersal from North America, the presumed origin of the genus Magnolia. The analysis and the extant Talauma distribution indicate a south to north recolonization. The ancestors of the other two Neotropical sections, Magnolia and Macrophylla, migrated around 19 mya from Asia to North America, radiating southward to the Neotropics afterwards, around 11 mya.ConclusionsOur results suggest that Neotropical magnolias originated from a North American ancestor. The current sections arrived at the region independently influenced by climatic processes such as temperature drops or the Miocene Climatic Optimum. Additionally, geological processes, such as the movement of the South and North American land masses and the emergence of the Panama isthmus, facilitated the migration between continents.

Complete Chloroplast Genome Analysis of Casearia kurzii: Gene Loss at the IR Boundary and Monophyletic Evolution Within Casearia.

Genomic analysis is crucial for understanding the evolutionary history, phylogenetic relationships, and effective conservation of plant species. Casearia kurzii is an important medicinal plant of the genus Casearia, but its complete chloroplast genome has not previously been reported, limiting genetic studies and conservation efforts. In this study, we assembled and annotated the complete chloroplast genome of C. kurzii using Illumina sequencing technology and conducted a comparative genomics analysis with 14 closely related species to clarify its phylogenetic position within Casearia. The chloroplast genome was 157,998 bp, showing a typical quadripartite structure. Key findings included: (1) the loss of the rpl22 gene at the IR boundary; (2) the identification of 60 simple sequence repeats (SSRs) and (3) the discovery of five candidate molecular markers for species-level identification. Phylogenetic analysis revealed that C. kurzii formed a strongly supported monophyletic clade (100% bootstrap support) with C. velutina, C. decandra, and C. glomerata, this clade originated approximately 15.8 million years ago. This study provides molecular tools for accurate identification and conservation of C. kurzii and related species, laying the foundation for exploring adaptive evolution within Casearia and advancing comparative genomics research.

Comparative Genomic and Phylogenetic Analysis of Chloroplasts in Citrus paradisi Mac.cv. Cocktail

Background: Citrus paradisi Mac. cv. Cocktail is globally valued for its abundant nutrients and bioactive compounds, particularly in tropical and subtropical regions. A novel albino phenotype mutant of C. paradisi Mac. cv. Cocktail (designated WT) was identified in Quzhou and subsequently named C. paradisi Mac. cv. Cocktail mosaic mutant (MT). To distinguish C. paradisi Mac. cv. Cocktail from conventional grapefruit cultivars and to elucidate genomic differences between WT and MT, this study conducted a comprehensive comparison of their chloroplast genomes with those of previously reported Citrus species. Methods: The complete chloroplast genomes of WT and MT were assembled through Illumina PE150 sequencing, enabling detailed comparative genomic and evolutionary studies. Results: The results revealed that both WT and MT chloroplast genomes exhibit a conserved quadripartite structure. Each genome measures 160,186 base pairs in length, with a uniform GC content of 38.5%. Annotation revealed 138 genes (91 protein-coding, 10 rRNA, 37 tRNA), 82 repeats, and A/U-biased codons. Genome boundaries and genome comparison showed WT and MT were identical but divergent from other Citrus. The 52 conserved protein-coding genes showed comparable selection pressures in both WT and MT. Phylogenetically, WT and MT are closely related and are distinguished from all of the traditional grapefruits. Conclusions: The albino phenotype of MT is unrelated to chloroplast variations. Chloroplast genomics supports C. paradisi cv. Cocktail’s differentiation from conventional grapefruits. This study expands the chloroplast genomic resources for Citrus and establishes a theoretical framework for future research on C. paradisi cv. Cocktail and related varieties.

Comparative analysis of complete chloroplast genomes of Cousinia (Asteraceae) species.

The study focused on analyzing the chloroplast genome structure and investigating the phylogenetic relationships among six species of the Cousinia genus. Within the Asteraceae family, the complete chloroplast genome sequences of six Cousinia species, ranging from 152,553 to 152,619 bp. The chloroplast genomes exhibit a characteristic quadripartite structure. The gene order is largely conserved across the genus, with an exception in the small single copy region, where a reverse orientation is observed in comparison to Cousinia thomsonii. A total of 131 genes were annotated, including 87 protein-coding genes, 36 tRNA genes, and 8 rRNA genes, with 18 genes showing duplication. Notably, 16 genes contain introns, with ycf3 and clpP carrying two introns each. Nucleotide diversity analysis revealed 412 polymorphic sites across 152,892 nucleotides in six Cousinia species. Higher nucleotide polymorphism levels were found in trnE-UUC - rpoB, trnL-UAA - trnF-GAA - ndhJ, rbcL, and ycf1 genomic regions, indicating possible genomic loci for species differentiation. Phylogenetic analysis using complete chloroplast genomes, demonstrated the genus Cousinia's phylogenetic placement within the Cardueae tribe, forming distinct clades that align with its traditional sectional classification. The Arctiinae subtribe, containing Cousinia, forms a monophyletic group with Arctium lappa, while Saussureinae were found to be polyphyletic. The findings suggest that while morphological traits are valuable in taxonomy, they may provide limited resolution compared to the more comprehensive phylogenetic insights obtained from chloroplast genome analysis.

Comprehensive analysis of complete chloroplast genome sequence of Morina L.

In order to understand the structure characteristics of the chloroplast genome of Morina and explore the phylogenetic relationships within Morina, the whole chloroplast genomes of Morina chinensis and Morina kokonorica were sequenced in this study. Together with other two species of Morina which have been sequenced, the chloroplast genome structure of Morina was compared. Analysis of codon usage preference, analysis of the contraction and expansion of IR region, and comparison of the whole sequence were done. A total of 129 functional genes were annotated in M. chinensis and M. kokonorica chloroplast genome, with one more rpl23 gene than other 2 species. Tetranucleotide and pentanucleotide were only detected in M. chinensis. The ycf1 gene distributed in the SSC region in Morina longifolia, but on the IRa/SSC boundary of M. chinensis, M. kokonorica and Morina chlorantha genome. And the sequence of M. longifolia is the longest due to the extension of LSC and SSC. Phylogenetic analysis showed that the Morinoideae was an independent subfamily separated from Dipsacoideae and the relationship between Linnaeoideae and Morinoideae was closer. The divergence time between Morinoideae and Linnaeoideae was about 67.28 Ma and the divergence time of Morinoideae and Dipsacoideae was about 72.58 Ma. This study is conducive to the development and utilization of the resources of Morina, and provides a theoretical basis for the further study of this species.

Phylogeny and evolutionary dynamics of the Rubia genus based on the chloroplast genome of Rubia tibetica

Rubia tibetica, a well-known medicinal plant, holds significant medicinal value. In this study, we sequenced and assembled the complete chloroplast genome of R. tibetica and conducted comparative analyses with four other Rubia species to provide insights into genome structure, selective pressure, and phylogenetic relationships. The chloroplast genome of R. tibetica was 154,901 bp in length and exhibited a typical quadripartite circular structure. Comparative analysis revealed a highly conserved genome structure among Rubia species, with genome sizes ranging from 153,555 bp to 155,108 bp and a GC content of approximately 37%. Codon usage analysis indicated a preference for A/U-ending codons. Selective pressure analysis identified relaxed selection in genes such as rps15 and petA, suggesting species-specific adaptive strategies. Two hypervariable regions, rps16-trnQ and psaJ-rps18, were experimentally validated as potential molecular markers through PCR amplification and sequencing. However, sequencing results of the rps16-trnQ region differed from the reference chloroplast genome, requiring further investigation. Phylogenetic analysis was performed using maximum likelihood (ML) based on the complete chloroplast genome sequences of five Rubia species and confirmed the monophyly of the Rubia genus, with R. tibetica occupying a basal position. This suggesting the retention of ancestral traits and adaptation to the unique environment of the Qinghai–Tibet Plateau. Molecular dating analysis further revealed divergence times consistent with geological and climatic events in the region. These findings provide critical insights into the evolutionary dynamics of Rubia species and offer valuable resources for their classification, conservation, and medicinal application.

Phylogenomics provides new insight into the phylogeny and diversification of Asian Lappula (Boraginaceae).

Phylogenomics provides new insight into the phylogeny and diversification of Asian Lappula (Boraginaceae).

The complete chloroplast genome sequences of three Cypripedium species and their phylogenetic analysis

Cypripedium macranthos Swartz, C. × ventricosum Swartz, and C. shanxiense S. C. Chen were highly promising ornamental plants. In this study, the latest complete chloroplast genome sequence of C. macranthos, C. × ventricosum, and C. shanxiense were reported using correct sample material from their native range, and their phylogenetic relationships with other related species were investigated preliminarily. The whole chloroplast genome lengths of C. macranthos, C. × ventricosum, and C. shanxiense were 181,030 bp, 175,385 bp, and 177,627 bp, respectively, with total GC contents of 34.56%, 34.48%, and 34.42%, respectively. Based on the maximum likelihood phylogenetic tree from the chloroplast genome sequences and internal transcribed spacer (ITS) sequences, it was confirmed that C. × ventricosum is most closely related to C. calceolus, and the idea that C. × ventricosum is an interspecific hybrid between C. calceolus and C. macranthos is supported. By integrating the results of phylogenetic analysis, genomic structural comparison, and considerations of sampling locations, it is evident that the former chloroplast genome of C. macranthos is inaccurate. This study provides crucial information for research on the phylogeny, genetics, and conservation of C. macranthos, C. × ventricosum, and C. shanxiense.

Reporting complete chloroplast genome of endangered red mulberry, useful for understanding hybridization and phylogenetic relationships

Introgressive hybridization of the North American native red mulberry (Morus rubra) with its invasive congener white mulberry (Morus alba) has severely threatened the genetic integrity of M. rubra, which is primarily found in pristine riparian forests. The major objectives of the present study were (1) to sequence, assemble, and annotate the complete chloroplast genome of M. rubra, and (2) to perform phylogenomic analyses of Morus species to assess their evolutionary history and hybridization events within the genus. We sampled 45 mulberry trees representing populations from eight US states for chloroplast genome sequencing. We found that the chloroplast genome of M. rubra ranged from 159,396 to 159,423 basepair (bp) and contained 128 genes coding for eight rRNAs, 37 tRNAs, and 83 proteins. The chloroplast genome of M. rubra was at least 103 bp larger than that of M. alba. The chloroplast DNA sequence polymorphism analysis of M. rubra showed the presence of 12 haplotypes. The chloroplast genome analysis across 12 Morus species identified trnK-UUU-rps16, psbI-trnG-UCC, psbC-psbZ, psbZ-trnM-CAU, rps4-trnT-UGU, trnT-UGU-trnL-UAA, ndhC-trnV-UAC, psbE-petL, clpP1, ndhF-rpl32, rpl32-trnL-UAG, and ccsA-ndhD as having higher DNA polymorphism (Pi > 0.01). Phylogenomic analysis of the 12 Morus species revealed distinct clades for Asian, North American, South American, and African Morus, supporting the monophyly of the genus. Divergence time analysis showed the most recent common ancestor of the genus Morus diverged 38.67 million years ago (MYA), separating the African clade of M. mesozygia and M. insignis from the others, while the American and Asian clades diverged 28.63 MYA. The results from this study provide insights into the chloroplast genome structure of M. rubra, offering a foundational data that bridges the knowledge gaps for addressing complex taxonomic complexities within the genus and for developing molecular markers to study population genetics, including introgressive hybridization.

The complete chloroplast genome and phylogenetic analysis of Cinnamomum daphnoides (Laurales: Lauraceae)

This study presents the complete chloroplast genome of Cinnamomum daphnoides (154,121 bp, GC 39.2%), a newly recorded species in China, revealing a typical quadripartite structure: a large single-copy region (93,688 bp, GC 37.9%), a small single-copy region (18,929 bp, GC 33.9%), and two inverted repeats (20,752 bp each, GC 44.3%). The genome harbors 126 genes (82 protein-coding, 36 tRNA, 8 rRNA). Phylogenetic analysis groups C. daphnoides with C. tamala, differing from prior studies. These findings clarify its systematic position within Cinnamomum and support its potential for coastal greening applications.

The First Complete Chloroplast Genome of Spider Flower (Cleome houtteana) Providing a Genetic Resource for Understanding Cleomaceae Evolution.

In the present study, the sequencing and analysis of the complete chloroplast genome of Cleome houtteana and its comparison with related species in the Cleomaceae family were carried out. The genome spans 157,714 base pairs (bp) and follows the typical chloroplast structure, consisting of a large single-copy (LSC) region (87,506 bp), a small single-copy (SSC) region (18,598 bp), and two inverted repeats (IRs) (25,805 bp each). We identified a total of 129 genes, including 84 protein-coding genes, 8 ribosomal RNA (rRNA) genes, and 37 transfer RNA (tRNA) genes. Our analysis of simple sequence repeats (SSRs) and repetitive elements revealed 91 SSRs, with a high number of A/T-rich mononucleotide repeats, which are common in chloroplast genomes. We also observed forward, palindromic, and tandem repeats, which are known to play roles in genome stability and evolution. When comparing C. houtteana with its relatives, we identified several highly variable regions, including ycf1, ycf2, and trnH-psbA, marking them as propitious molecular markers for the identification of species as well as phylogenetic studies. We examined the inverted repeat (IR) boundaries and found minor shifts in comparison to the other species, particularly in the ycf1 gene region, which is a known hotspot for evolutionary changes. Additionally, our analysis of selective pressures (Ka/Ks ratios) showed that most genes are under strong purifying selection, preserving their essential functions. A sliding window analysis of nucleotide diversity (Pi) identified several regions with high variability, such as trnH-psbA, ycf1, ndhI-ndhG, and trnL-ndhF, highlighting their potential for use in evolutionary and population studies. Finally, our phylogenetic analysis, using complete chloroplast genomes from species within Cleomaceae, Brassicaceae, and Capparaceae, confirmed that C. houtteana belongs within the Cleomaceae family. It showed a close evolutionary relationship with Tarenaya hassleriana and Sieruela rutidosperma, supporting previous taxonomic classifications. The findings from the current research offer invaluable insights regarding genomic structure, evolutionary adaptations, and phylogenetic relationships of C. houtteana, providing a foundation for future research on species evolution, taxonomy, and conservation within the Cleomaceae family.

Comparative analysis of chloroplast genomes in three Araceae species: genomic difference, genetic distance and species morphology association.

Many species in the Araceae have extremely high medicinal value, while the chloroplast genome is relatively conserved, and the encoded and expressed bioactive substances are also abundant. Therefore, chloroplast genomes can serve as one of the basis for species evolution and are extremely important for individual material accumulation. To study the relationship between the chloroplast genome and morphology of target species, this study selected three Araceae species for chloroplast genome sequencing assembly, downloaded the complete chloroplast genomes sequences of another 11 Araceae species. Grouping based on genetic distance, we analyze the association between chloroplast genome structure and morphology. The results showed that there were significant differences in genome size among the three species, but Relative Synonymous Codon Usage (RSCU) exhibited high similarity; Based on the phylogenetic tree, these 14 species can be divided into three branches, with differences in genes such as rrn4, rrn5, rrn23, and trnN among species within each branch; Morphologically, the length of the male inflorescence in BranchⅢ is significantly greater than that in BranchⅡ; There is a strong positive correlation between the length of the plant stem and the three parameters (Length of LSC, Length of SSC and Length of chloroplast genome) of the genome. This study conducted correlation research from the perspective of chloroplast genome and species morphology. On the one hand, the genetic distance and chloroplast genome structure differences between the target species were determined, and on the other hand, explored the correlation between chloroplast genome and species morphology, providing a theoretical basis for the study of phylogenetic relationships and morphology of Araceae species.

The complete chloroplast genome sequence of Enkianthus perulatus (Miq.) C.K.Schneid. (Ericaceae)

Enkianthus perulatus (Miq.) C.K.Schneid. is a popular ornamental plant in Japan, for which the chloroplast genome has not been previously reported. Its complete chloroplast genome was therefore determined, using a high-throughput sequencing technique. The total length of the E. perulatus chloroplast genome was 157,256 bp, comprising a large single copy region of 89,680 bp and a small single copy region of 20,472 bp, separated by a pair of 23,552 bp inverted repeat regions. A phylogenetic analysis, based on the chloroplast genome, indicated that E. perulatus is the earliest diverged species within Ericaceae. The chloroplast genome structure of E. perulatus is similar to species from families within Ericales, but not other species of Ericaceae. The presented chloroplast genome will be useful for further systematic analyses and planning conservation strategies.