scholarly journals Comparative chloroplast genomics of Fritillaria (Liliaceae), inferences for phylogenetic relationships between Fritillaria and Lilium and genome evolution

2019 ◽  
Author(s):  
Jiao Huang ◽  
Yan Yu ◽  
Yan-Mei Liu ◽  
Deng-Feng Xie ◽  
Xing-Jin He ◽  
...  

Abstract Background Fritillaria is a genus consisting of about 140 species that has important medicinal and horticultural values. The monophyly of Fritillaria and phylogenetic relationships with Lilium were previously not fully resolved. The study involved the most comprehensive chloroplast genomes samples to date referring to Old and New World clades of Fritillaria as identified in earlier studies.Results We reported and compared eleven newly sequenced whole-plastome sequences of Fritillaria as well as characterization of SSRs and repeat sequence. These 11 plastomes proved highly similar in overall size (151,652-152,434bp), genome structure, gene content and order; Comparing them with other species of Liliales (6 out of 10 families) indicated the same similarity but showed some structural variations due to the contraction or expansion of the IR regions out or into of adjacent single-copy regions. A/T mononucleotides, palindromic and forward repeats were the most common types. Six hypervariable regions ( rps16 - trnQ, rbcL - accD, accD - psaI, psaJ - rpl33, petD - rpoA and rpl32 - trnL ) were discovered based on 26 Fritillaria whole-plastomes to be potential molecular markers. 26 species of Fritillaria plastomes and 21 species of Lilium plastomes were combined in a phylogenomic study with 3 Cardiocrinum species as out groups. Fritillaria was monophyly with moderate support as sister to Lilium based on 64 protein-coding genes (CDS) and the interspecific relationship within subgenus Fritillaria has strong resolution. The topology recovered from the whole plastome and single-copy gene data sets was the same as for coding gene data, but weak support for monophyly of Fritillaria .Conclusions The phylogenomic analysis reconstructed a topology that had some incongruences with previous studies. The six hypervariable regions can be used as candidate DNA barcodes for global genetic diversity detection of Fritillaria . The phylogenomic framework from this study can guide extensive genomic sampling to further discern the relationships among the Old and New World clades of Fritillaria and Lilium .

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 109
Author(s):  
Kuan Liu ◽  
Rong Wang ◽  
Xiu-Xiu Guo ◽  
Xue-Jie Zhang ◽  
Xiao-Jian Qu ◽  
...  

Eragrostideae Stapf, the second-largest tribe in Chloridoideae (Poaceae), is a taxonomically complex tribe. In this study, chloroplast genomes of 13 Eragrostideae species were newly sequenced and used to resolve the phylogenetic relationships within Eragrostideae. Including seven reported chloroplast genomes from Eragrostideae, the genome structure, number and type of genes, codon usage, and repeat sequences of 20 Eragrostideae species were analyzed. The length of these chloroplast genomes varied from 130,773 bp to 135,322 bp. These chloroplast genomes showed a typical quadripartite structure, including a large single-copy region (77,993–80,643 bp), a small single-copy region (12,410–12,668 bp), and a pair of inverted repeats region (19,394–21,074 bp). There were, in total, 129–133 genes annotated in the genome, including 83–87 protein-coding genes, eight rRNA genes, and 38 tRNA genes. Forward and palindromic repeats were the most common repeat types. In total, 10 hypervariable regions (rpl22, rpoA, ndhF, matK, trnG–UCC-trnT–GGU, ndhF–rpl32, ycf4–cemA, rpl32–trnL–UAG, trnG–GCC–trnfM–CAU, and ccsA–ndhD) were found, which can be used as candidate molecular markers for Eragrostideae. Phylogenomic studies concluded that Enneapogon diverged first, and Eragrostis including Harpachne is the sister to Uniola. Furthermore, Harpachne harpachnoides is considered as a species of Eragrostis based on morphological and molecular evidence. In addition, the interspecies relationships within Eragrostis are resolved based on complete chloroplast genomes. This study provides useful chloroplast genomic information for further phylogenetic analysis of Eragrostideae.


2018 ◽  
Vol 19 (12) ◽  
pp. 3780 ◽  
Author(s):  
Dingxuan He ◽  
Andrew Gichira ◽  
Zhizhong Li ◽  
John Nzei ◽  
Youhao Guo ◽  
...  

The order Nymphaeales, consisting of three families with a record of eight genera, has gained significant interest from botanists, probably due to its position as a basal angiosperm. The phylogenetic relationships within the order have been well studied; however, a few controversial nodes still remain in the Nymphaeaceae. The position of the Nuphar genus and the monophyly of the Nymphaeaceae family remain uncertain. This study adds to the increasing number of the completely sequenced plastid genomes of the Nymphaeales and applies a large chloroplast gene data set in reconstructing the intergeneric relationships within the Nymphaeaceae. Five complete chloroplast genomes were newly generated, including a first for the monotypic Euryale genus. Using a set of 66 protein-coding genes from the chloroplast genomes of 17 taxa, the phylogenetic position of Nuphar was determined and a monophyletic Nymphaeaceae family was obtained with convincing statistical support from both partitioned and unpartitioned data schemes. Although genomic comparative analyses revealed a high degree of synteny among the chloroplast genomes of the ancient angiosperms, key minor variations were evident, particularly in the contraction/expansion of the inverted-repeat regions and in RNA-editing events. Genome structure, and gene content and arrangement were highly conserved among the chloroplast genomes. The intergeneric relationships defined in this study are congruent with those inferred using morphological data.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8450 ◽  
Author(s):  
Sunan Huang ◽  
Xuejun Ge ◽  
Asunción Cano ◽  
Betty Gaby Millán Salazar ◽  
Yunfei Deng

The genus Dicliptera (Justicieae, Acanthaceae) consists of approximately 150 species distributed throughout the tropical and subtropical regions of the world. Newly obtained chloroplast genomes (cp genomes) are reported for five species of Dilciptera (D. acuminata, D. peruviana, D. montana, D. ruiziana and D. mucronata) in this study. These cp genomes have circular structures of 150,689–150,811 bp and exhibit quadripartite organizations made up of a large single copy region (LSC, 82,796–82,919 bp), a small single copy region (SSC, 17,084–17,092 bp), and a pair of inverted repeat regions (IRs, 25,401–25,408 bp). Guanine-Cytosine (GC) content makes up 37.9%–38.0% of the total content. The complete cp genomes contain 114 unique genes, including 80 protein-coding genes, 30 transfer RNA (tRNA) genes, and four ribosomal RNA (rRNA) genes. Comparative analyses of nucleotide variability (Pi) reveal the five most variable regions (trnY-GUA-trnE-UUC, trnG-GCC, psbZ-trnG-GCC, petN-psbM, and rps4-trnL-UUA), which may be used as molecular markers in future taxonomic identification and phylogenetic analyses of Dicliptera. A total of 55-58 simple sequence repeats (SSRs) and 229 long repeats were identified in the cp genomes of the five Dicliptera species. Phylogenetic analysis identified a close relationship between D. ruiziana and D. montana, followed by D. acuminata, D. peruviana, and D. mucronata. Evolutionary analysis of orthologous protein-coding genes within the family Acanthaceae revealed only one gene, ycf15, to be under positive selection, which may contribute to future studies of its adaptive evolution. The completed genomes are useful for future research on species identification, phylogenetic relationships, and the adaptive evolution of the Dicliptera species.


2019 ◽  
Vol 42 (4) ◽  
pp. 601-611 ◽  
Author(s):  
Yan Li ◽  
Liukun Jia ◽  
Zhihua Wang ◽  
Rui Xing ◽  
Xiaofeng Chi ◽  
...  

Abstract Saxifraga sinomontana J.-T. Pan & Gornall belongs to Saxifraga sect. Ciliatae subsect. Hirculoideae, a lineage containing ca. 110 species whose phylogenetic relationships are largely unresolved due to recent rapid radiations. Analyses of complete chloroplast genomes have the potential to significantly improve the resolution of phylogenetic relationships in this young plant lineage. The complete chloroplast genome of S. sinomontana was de novo sequenced, assembled and then compared with that of other six Saxifragaceae species. The S. sinomontana chloroplast genome is 147,240 bp in length with a typical quadripartite structure, including a large single-copy region of 79,310 bp and a small single-copy region of 16,874 bp separated by a pair of inverted repeats (IRs) of 25,528 bp each. The chloroplast genome contains 113 unique genes, including 79 protein-coding genes, four rRNAs and 30 tRNAs, with 18 duplicates in the IRs. The gene content and organization are similar to other Saxifragaceae chloroplast genomes. Sixty-one simple sequence repeats were identified in the S. sinomontana chloroplast genome, mostly represented by mononucleotide repeats of polyadenine or polythymine. Comparative analysis revealed 12 highly divergent regions in the intergenic spacers, as well as coding genes of matK, ndhK, accD, cemA, rpoA, rps19, ndhF, ccsA, ndhD and ycf1. Phylogenetic reconstruction of seven Saxifragaceae species based on 66 protein-coding genes received high bootstrap support values for nearly all identified nodes, suggesting a promising opportunity to resolve infrasectional relationships of the most species-rich section Ciliatae of Saxifraga.


Author(s):  
Weiwen Wang ◽  
Robert Lanfear

Abstract The chloroplast genome usually has a quadripartite structure consisting of a large single copy region and a small single copy region separated by two long inverted repeats. It has been known for some time that a single cell may contain at least two structural haplotypes of this structure, which differ in the relative orientation of the single copy regions. However, the methods required to detect and measure the abundance of the structural haplotypes are labour-intensive, and this phenomenon remains understudied. Here we develop a new method, Cp-hap, to detect all possible structural haplotypes of chloroplast genomes of quadripartite structure using long-read sequencing data. We use this method to conduct a systematic analysis and quantification of chloroplast structural haplotypes in 61 land plant species across 19 orders of Angiosperms, Gymnosperms and Pteridophytes. Our results show that there are two chloroplast structural haplotypes which occur with equal frequency in most land plant individuals. Nevertheless, species whose chloroplast genomes lack inverted repeats or have short inverted repeats have just a single structural haplotype. We also show that the relative abundance of the two structural haplotypes remains constant across multiple samples from a single individual plant, suggesting that the process which maintains equal frequency of the two haplotypes operates rapidly, consistent with the hypothesis that flip-flop recombination mediates chloroplast structural heteroplasmy. Our results suggest that previous claims of differences in chloroplast genome structure between species may need to be revisited.


2020 ◽  
Author(s):  
Benwen Liu ◽  
Yu Xin Hu ◽  
Zheng Yu Hu ◽  
Guo Xiang Liu ◽  
Huan Zhu

Abstract Background Order Chaetophorales currently includes six families, namely Schizomeridaceae, Aphanochaetaceae, Barrancaceae, Uronemataceae, Fritschiellaceae, and Chaetophoraceae. Most studies have primarily focused on intergeneric phylogenetic relationships within this order and the phylogenetic relationships with four other Chlorophycean orders (Chaetophorales, Chaetopeltidales and Oedogoniales, and Volvocales). This study aimed to phylogenetically reconstruct order Chaetophorales and determine the taxonomic scheme and to further the current understanding of the evolution of order Chaetophorales. The taxonomic scheme of Chaetophorales has been inferred primarily through phylogenetic analysis based on rDNA sequences and phylogenetic relationships among families in order Chaetophorales remain unclear. Results In present study, seven complete and five fragmentary chloroplast genomes were harvested. Phylogenomic and comparative genomic analysis were performed to determine the taxonomic scheme within Chaetophorales. Consequently, Oedogoniales was found to be a sister to a clade linking Chaetophorales and Chaetopeltidales, Schizomeriaceae, and Aphanochaetaceae clustered into a well-resolved basal clade in Chaetophorales, inconsistent with the results of phylogenetic analysis based on rDNA sequences. Comparative genomic analyses revealed that the chloroplast genomes of Schizomeriaceae and Aphanochaetaceae were highly conserved and homologous, highlighting the closest relationship in this order. Germination types of zoospores precisely correlated with the phylogenetic relationships. Conclusions In conclusion, chloroplast genome structure analyses, synteny analyses, and zoospore germination analyses were concurrent with phylogenetic analyses based on the chloroplast genome, and all of them robustly determined the unique taxonomic scheme of Chaetophorales and the relationships of Oedogoniales, Chaetophorales, and Chaetopeltidales.


Plants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 133 ◽  
Author(s):  
Jiao Huang ◽  
Yan Yu ◽  
Yan-Mei Liu ◽  
Deng-Feng Xie ◽  
Xing-Jin He ◽  
...  

Fritillaria is a genus that has important medicinal and horticultural values. The study involved the most comprehensive chloroplast genome samples referring to Old and New World clades of Fritillaria for marker selection and phylogenetic studies. We reported and compared eleven newly sequenced whole-plastome sequences of Fritillaria which proved highly similar in overall size (151,652–152,434 bp), genome structure, gene content, and order. Comparing them with other species of Liliales (6 out of 10 families) indicated the same similarity but showed some structural variations due to the contraction or expansion of the inverted repeat (IR) regions. A/T mononucleotides, palindromic, and forward repeats were the most common types. Six hypervariable regions (rps16-trnQ, rbcL-accD, accD-psaI, psaJ-rpl33, petD-rpoA, and rpl32-trnL) were discovered based on 26 Fritillaria whole-plastomes to be potential molecular markers. Based on the plastome data that were collected from 26 Fritillaria and 21 Lilium species, a phylogenomic study was carried out with three Cardiocrinum species as outgroups. Fritillaria was sister to Lilium with a high support value, and the interspecies relationships within subgenus Fritillaria were resolved very well. The six hypervariable regions can be used as candidate DNA barcodes of Fritillaria and the phylogenomic framework can guide extensive genomic sampling for further phylogenetic analyses.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jin Xu ◽  
Chen Liu ◽  
Yun Song ◽  
Mingfu Li

The genus Pennisetum (Poaceae) is both a forage crop and staple food crop in the tropics. In this study, we obtained chloroplast genome sequences of four species of Pennisetum (P. alopecuroides, P. clandestinum, P. glaucum, and P. polystachion) using Illumina sequencing. These chloroplast genomes have circular structures of 136,346–138,119 bp, including a large single-copy region (LSC, 79,380–81,186 bp), a small single-copy region (SSC, 12,212–12,409 bp), and a pair of inverted repeat regions (IRs, 22,284–22,372 bp). The overall GC content of these chloroplast genomes was 38.6–38.7%. The complete chloroplast genomes contained 110 different genes, including 76 protein-coding genes, 30 transfer RNA (tRNA) genes, and four ribosomal RNA (rRNA) genes. Comparative analysis of nucleotide variability identified nine intergenic spacer regions (psbA-matK, matK-rps16, trnN-trnT, trnY-trnD-psbM, petN-trnC, rbcL-psaI, petA-psbJ, psbE-petL, and rpl32-trnL), which may be used as potential DNA barcodes in future species identification and evolutionary analysis of Pennisetum. The phylogenetic analysis revealed a close relationship between P. polystachion and P. glaucum, followed by P. clandestinum and P. alopecuroides. The completed genomes of this study will help facilitate future research on the phylogenetic relationships and evolution of Pennisetum species.


2020 ◽  
Author(s):  
Benwen Liu(Former Corresponding Author) ◽  
Yu Xin Hu ◽  
Zheng Yu Hu ◽  
Guo Xiang Liu ◽  
Huan Zhu(New Corresponding Author)

Abstract Background: Order Chaetophorales currently includes six families, namely Schizomeridaceae, Aphanochaetaceae, Barrancaceae, Uronemataceae, Fritschiellaceae, and Chaetophoraceae. The phylogenetic relationships of Chaetophorales have been inferred primarily through phylogenetic analysis based on rDNA sequences. Most studies have primarily focused on intergeneric phylogenetic relationships within this order and the phylogenetic relationships with four other Chlorophycean orders (Chaetophorales, Chaetopeltidales and Oedogoniales, and Volvocales). The phylogenetic relationships among families in order Chaetophorales remain unclear. This study aimed to phylogenetically reconstruct order Chaetophorales and determine the taxonomic scheme and to further the current understanding of the evolution of order Chaetophorales . Results: In the present study, seven complete and five fragmentary chloroplast genomes were harvested. Phylogenomic and comparative genomic analysis were performed to determine the taxonomic scheme within Chaetophorales. Consequently, Oedogoniales was found to be a sister to a clade linking Chaetophorales and Chaetopeltidales. Schizomeriaceae, and Aphanochaetaceae clustered into a well-resolved basal clade in Chaetophorales, inconsistent with the results of phylogenetic analysis based on rDNA sequences. Comparative genomic analyses revealed that the chloroplast genomes of Schizomeriaceae and Aphanochaetaceae were highly conserved and homologous, highlighting the closest relationship in this order. Germination types of zoospores precisely correlated with the phylogenetic relationships. Conclusions: chloroplast genome structure analyses, synteny analyses, and zoospore germination analyses were concurrent with phylogenetic analyses based on the chloroplast genome, and all of them robustly determined the unique taxonomic scheme of Chaetophorales and the relationships of Oedogoniales, Chaetophorales, and Chaetopeltidales.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6320 ◽  
Author(s):  
Zhen Yang ◽  
Guixi Wang ◽  
Qinghua Ma ◽  
Wenxu Ma ◽  
Lisong Liang ◽  
...  

Background Previous phylogenetic conclusions on the family Betulaceae were based on either morphological characters or traditional single loci, which may indicate some limitations. The chloroplast genome contains rich polymorphism information, which is very suitable for phylogenetic studies. Thus, we sequenced the chloroplast genome sequences of three Betulaceae species and performed multiple analyses to investigate the genome variation, resolve the phylogenetic relationships, and clarify the divergence history. Methods Chloroplast genomes were sequenced using the high-throughput sequencing. A comparative genomic analysis was conducted to examine the global genome variation and screen the hotspots. Three chloroplast partitions were used to reconstruct the phylogenetic relationships using Maximum Likelihood and Bayesian Inference approaches. Then, molecular dating and biogeographic inferences were conducted based on the whole chloroplast genome data. Results Betulaceae chloroplast genomes consisted of a small single-copy region and a large single copy region, and two copies of inverted repeat regions. Nine hotspots can be used as potential DNA barcodes for species delimitation. Phylogenies strongly supported the division of Betulaceae into two subfamilies: Coryloideae and Betuloideae. The phylogenetic position of Ostryopsis davidiana was controversial among different datasets. The divergence time between subfamily Coryloideae and Betuloideae was about 70.49 Mya, and all six extant genera were inferred to have diverged fully by the middle Oligocene. Betulaceae ancestors were probably originated from the ancient Laurasia. Discussions This research elucidates the potential of chloroplast genome sequences in the application of developing molecular markers, studying evolutionary relationships and historical dynamic of Betulaceae.It also reveals the advantages of using chloroplast genome data to illuminate those phylogenies that have not been well solved yet by traditional approaches in other plants.


Sign in / Sign up

Export Citation Format

Share Document