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491 result(s) for "matK"
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A new subfamily classification of the Leguminosae based on a taxonomically comprehensive phylogeny
The classification of the legume family proposed here addresses the long-known non-monophyly of the traditionally recognised subfamily Caesalpinioideae, by recognising six robustly supported monophyletic subfamilies. This new classification uses as its framework the most comprehensive phylogenetic analyses of legumes to date, based on plastid matK gene sequences, and including near-complete sampling of genera (698 of the currently recognised 765 genera) and ca. 20% (3696) of known species. The matK gene region has been the most widely sequenced across the legumes, and in most legume lineages, this gene region is sufficiently variable to yield well-supported clades. This analysis resolves the same major clades as in other phylogenies of whole plastid and nuclear gene sets (with much sparser taxon sampling). Our analysis improves upon previous studies that have used large phylogenies of the Leguminosae for addressing evolutionary questions, because it maximises generic sampling and provides a phylogenetic tree that is based on a fully curated set of sequences that are vouchered and taxonomically validated. The phylogenetic trees obtained and the underlying data are available to browse and download, facilitating subsequent analyses that require evolutionary trees. Here we propose a new community-endorsed classification of the family that reflects the phylogenetic structure that is consistently resolved and recognises six subfamilies in Leguminosae: a recircumscribed Caesalpinioideae DC., Cercidoideae Legume Phylogeny Working Group (stat. nov.), Detarioideae Burmeist., Dialioideae Legume Phylogeny Working Group (stat. nov.), Duparquetioideae Legume Phylogeny Working Group (stat. nov.), and Papilionoideae DC. The traditionally recognised subfamily Mimosoideae is a distinct clade nested within the recircumscribed Caesalpinioideae and is referred to informally as the mimosoid clade pending a forthcoming formal tribal and/or clade-based classification of the new Caesalpinioideae. We provide a key for subfamily identification, descriptions with diagnostic charactertistics for the subfamilies, figures illustrating their floral and fruit diversity, and lists of genera by subfamily. This new classification of Leguminosae represents a consensus view of the international legume systematics community; it invokes both compromise and practicality of use.
DNA barcode for land plants
DNA barcoding involves sequencing a standard region of DNA as a tool for species identification. However, there has been no agreement on which region(s) should be used for barcoding land plants. To provide a community recommendation on a standard plant barcode, we have compared the performance of 7 leading candidate plastid DNA regions (atpF-atpH spacer, matK gene, rbcL gene, rpoB gene, rpoC1 gene, psbK-psbI spacer, and trnH-psbA spacer). Based on assessments of recoverability, sequence quality, and levels of species discrimination, we recommend the 2-locus combination of rbcL+matK as the plant barcode. This core 2-locus barcode will provide a universal framework for the routine use of DNA sequence data to identify specimens and contribute toward the discovery of overlooked species of land plants.
Gene loss, genome rearrangement, and accelerated substitution rates in plastid genome of Hypericum ascyron (Hypericaceae)
Background Comparative genomic analysis exhibits dynamic evolution of plastid genome (plastome) in the clusioid clade of Malpighiales, which comprise five families, including multiple inversions and gene losses. Little is known about the plastome evolution in Hypericaceae, a large family in the clade. Only the plastome of one species, Cratoxylum cochinchinense, has been published. Results We generated a complete plastome sequence for Hypericum ascyron , providing the first complete plastome from the tribe Hypericeae (Hypericaceae). The H. ascyron plastome exhibits dynamic changes in gene and intron content, structure, and sequence divergence compared to the C. cochinchinense plastome from the tribe Cratoxyleae (Hypericaceae). Transcriptome data determined the evolutionary fate of the missing plastid genes infA , rps7 , rps16 , rpl23 , and rpl32 in H. ascyron . Putative functional transfers of infA , rps7, and rpl32 were detected to the nucleus, whereas rps16 and rpl23 were substituted by nuclear-encoded homologs. The plastid rpl32 was integrated into the nuclear-encoded SODcp gene. Our findings suggested that the transferred rpl32 had undergone subfunctionalization by duplication rather than alternative splicing. The H. ascyron plastome rearrangements involved seven inversions, at least three inverted repeat (IR) boundary shifts, which generated gene relocations and duplications. Accelerated substitution rates of plastid genes were observed in the H. ascyron plastome compared with that of C. cochinchinense plastid genes. The higher substitution rates in the accD and clpP were correlated with structural change, including a large insertion of amino acids and losses of two introns, respectively. In addition, we found evidence of positive selection of the clpP , matK , and rps3 genes in the three branches related to H. ascyron . In particular, the matK gene was repeatedly under selection within the family Hypericaceae. Selective pressure in the H. ascyron matK gene was associated with the loss of trnK -UUU and relocation into the IR region. Conclusions The Hypericum ascyron plastome sequence provides valuable information for improving the understanding of plastome evolution among the clusioid of the Malpighiales. Evidence for intracellular gene transfer from the plastid to the nucleus was detected in the nuclear transcriptome, providing insight into the evolutionary fate of plastid genes in Hypericaceae.
Comparison of matK and rbcL DNA barcodes for genetic classification of jewel orchid accessions in Vietnam
Jewel orchid is the common name of several orchid species which can be alike in morphological characteristics, but variable in medicinal properties. At present, two DNA barcode loci, namely, maturase K (matK) and ribulose 1,5-biphosphate carboxylase (rbcL), are intensively utilized for plant identification. However, the discrimination effectiveness of these loci is variable among plant species. This study was carried out to compare the identifying efficacy of these two loci on jewel orchid population collected throughout Vietnam. The results revealed that 21 jewel orchid accessions studied were segregated into four different species with significant variations. The discrimination power of matK and rbcL markers in this jewel orchid study displayed different efficiency level. The rbcL gene has higher distinguishing potential than either matK gene alone or the combination of both genes. The findings of this project could provide valuable information that is necessary for classification, plant origin identification, breeding, and conservation program of jewel orchid in Vietnam.
The use of DNA barcoding as a tool for the conservation biogeography of subtropical forests in China
Aim Rapid and accurate species identification is the foundation for biodiversity assessment. DNA barcoding has been shown to be an effective tool to overcome the taxonomic impediment to facilitate biodiversity conservation in temperate forests. However, this tool has rarely been considered for use in tropical forests. This study aims to investigate the utility and species resolution of DNA barcoding in a subtropical region. Location The Dinghushan National Nature Reserve (DNNR) in China. Methods A DNA barcoding database was constructed for 531 trees present in the DNNR. We used a phylogenetic method (neighbour-joining trees) and sequence similarity (all-to-all BLASTn searches) to evaluate the utility and species resolution of five DNA barcode regions (rbcL, matK, ITS, ITS2 and trnH-psbA), both singly and in combinations of two or three region. Results The combination of rbcL + matK + ITS had the highest species resolution (94.19%). However, when considering the difficulty of sequence recoverability, rbcL + ITS2 performed best (64.64%). Species resolution for large genera containing more than two species was substantially lower than that for small genera with one and two species per genus. Local small spatial scales (1-ha quadrats) resulted in moderately improved species resolution (70.82% for rbcL + ITS2) compared to larger spatial scales (20 and 1133 ha). We document incongruent signals between nuclear and cpDNA regions and the challenges associated with barcoding large genera inherent to subtropical floras. Main conclusions This study considerably expands the global DNA barcode database for subtropical trees. Based on cost-effectiveness and the trade-off between sequence recovery and species resolution, we suggest that the rbcL + ITS2 barcode combination is an effective tool for documenting plant diversity in the DNNR. This study also sheds some light on the limitations and challenges for the application of barcoding to conservation biogeography in subtropical forests.
Morphological and molecular characterization of two species of genus Ageratum
Background The species of genus Ageratum (family Asteraceae) are distributed in various parts of the world. Ageratum conyzoides and A. houstonianum are the most commonly occurring species in India. These species are quite similar in their morphology thus creating a challenge in identification during the field survey and taxonomic validation. The accurate identification of the species is highly significant especially when those are of medicinal interest. To overcome the barriers in morphological based identification, DNA barcoding has been employed during the present investigation. Methods and results Morphological and DNA barcodes matK and ITS genes, were employed to differentiate between Ageratum conyzoides and A. houstonianum . The obtained matK and ITS gene sequences were submitted to GenBank and BOLD system to obtain accession numbers. The DNA sequences were aligned with database sequences using BLAST and phylogenetic trees were constructed through neighbor-joining algorithm in MEGA 11 software. The distinguish features of A. conyzoides include ovate to elliptic-oblong leaves with a cuneate base and inflorescence heads forming domed to flat-topped clusters. However, A. houstonianum has triangular to ovate leaves with a cordate to truncate base, cymose clusters in the inflorescence and stipulate glandular involucre bracts. The matK gene has shown the highest identity percentages (100%) for A. houstonianum and 99.87% for A. conyzoides . The phylogenetic tree analysis has demonstrated a close association of A. conyzoides and A. houstonianum with their respective species, supported by bootstrap values in the matK and ITS trees. Conclusion This study revealed that morphological and molecular data can be successfully utilized in the identification of A. conyzoides and A. houstonianum . The matK and ITS barcodes provide promising results in the identification of Ageratum species, with their phylogeny supporting classification within the family asteraceae.
Highly Resolved Papilionoid Legume Phylogeny Based on Plastid Phylogenomics
Comprising 501 genera and around 14,000 species, Papilionoideae is not only the largest subfamily of Fabaceae (Leguminosae; legumes), but also one of the most extraordinarily diverse clades among angiosperms. Papilionoids are a major source of food and forage, are ecologically successful in all major biomes, and display dramatic variation in both floral architecture and plastid genome (plastome) structure. Plastid DNA-based phylogenetic analyses have greatly improved our understanding of relationships among the major groups of Papilionoideae, yet the backbone of the subfamily phylogeny remains unresolved. In this study, we sequenced and assembled 39 new plastomes that are covering key genera representing the morphological diversity in the subfamily. From 244 total taxa, we produced eight datasets for maximum likelihood (ML) analyses based on entire plastomes and/or concatenated sequences of 77 protein-coding sequences (CDS) and two datasets for multispecies coalescent (MSC) analyses based on individual gene trees. We additionally produced a combined nucleotide dataset comprising CDS plus matK gene sequences only, in which most papilionoid genera were sampled. A ML tree based on the entire plastome maximally supported all of the deep and most recent divergences of papilionoids (223 out of 236 nodes). The Swartzieae, ADA (Angylocalyceae, Dipterygeae, and Amburaneae), Cladrastis, Andira, and Exostyleae clades formed a grade to the remainder of the Papilionoideae, concordant with nine ML and two MSC trees. Phylogenetic relationships among the remaining five papilionoid lineages (Vataireoid, Dermatophyllum , Genistoid s.l., Dalbergioid s.l., and Baphieae + Non-Protein Amino Acid Accumulating or NPAAA clade) remained uncertain, because of insufficient support and/or conflicting relationships among trees. Our study fully resolved most of the deep nodes of Papilionoideae, however, some relationships require further exploration. More genome-scale data and rigorous analyses are needed to disentangle phylogenetic relationships among the five remaining lineages.
Molecular Study of the Two Species of senna L. in Iraq
In this study, genetic information was obtained as evidence of proper identification to detect the divergence between the species belonging to the genus Senna.L, namely Senna alata (Linnaeus) Roxb and Senna didymobotrya (fresen) of the legume family Leguminosae (Fabaceae). Field work was carried out during the growing season of 10/1/2023. DNA was extracted from fresh leaves of the two plant species. We used the polymerase chain reaction - genomic reaction of the chloroplast DNA. The matK region of the chloroplast DNA was amplified using primers and the nucleotide sequences of each species were obtained. The results showed that the molecular weight of the band size for the two species was 902 Pb and according to the barcode classification, the entire genome is considered as a super barcode for the two samples under study. The matK gene sequence was obtained from the GenBank and used for analysis. The phylogenetic tree was designed to identify the ideal regions that can be used to determine the relationships between the two species.It was compared with the global plant sequences closest to the two species and the sequence was registered in the gene bank. The genetic tree showed that the species Senna didymobotrya deposited under the serial number MN243366.1 is the closest global species to the plant Senna didymobotrya under study in Iraq and is linked by up to 100% about the rest of the species. The research also showed that the most global plant related to the species Senna alata is the plant Senna alata registered under the serial number (LC385932.1) at a rate of 99%.
Validation of the ITS2 Region as a Novel DNA Barcode for Identifying Medicinal Plant Species
Background: The plant working group of the Consortium for the Barcode of Life recommended the two-locus combination of rbcL + matK as the plant barcode, yet the combination was shown to successfully discriminate among 907 samples from 550 species at the species level with a probability of 72%. The group admits that the two-locus barcode is far from perfect due to the low identification rate, and the search is not over. Methodology/Principal Findings: Here, we compared seven candidate DNA barcodes (psbA-trnH, matK, rbcL, rpoC1, ycf5, ITS2, and ITS) from medicinal plant species. Our ranking criteria included PCR amplification efficiency, differential intra- and inter-specific divergences, and the DNA barcoding gap. Our data suggest that the second internal transcribed spacer (ITS2) of nuclear ribosomal DNA represents the most suitable region for DNA barcoding applications. Furthermore, we tested the discrimination ability of ITS2 in more than 6600 plant samples belonging to 4800 species from 753 distinct genera and found that the rate of successful identification with the ITS2 was 92.7% at the species level. Conclusions: The ITS2 region can be potentially used as a standard DNA barcode to identify medicinal plants and their closely related species. We also propose that ITS2 can serve as a novel universal barcode for the identification of a broader range of plant taxa.
Morpho-anatomical characterization and DNA barcoding of Artemesia vulgaris L
Abstract Artemisia vulgaris L. belongs to Asteraceae, is a herbal plant that has various benefits in the medical field, so that its use in the medical field can be explored optimally, the plant must be thoroughly identified. This study aims to identify A. vulgaris both in terms of descriptive morpho-anatomy and DNA barcoding using BLAST and phylogenetic tree reconstruction. The morpho-anatomical character was observed on root, stem, and leaf. DNA barcoding analysis was carried out through amplification and alignment of the rbcL and matK genes. All studies were conducted on three samples from Taman Husada (Medicinal Plant Garden) Graha Famili Surabaya, Indonesia. The anatomical slide was prepared by the paraffin method. Morphological studies revealed that the leaves of A. vulgaris both on the lower-middle part and on the upper part of the stem have differences, especially in the character of the stipules, petioles, and incisions they have. Meanwhile, from the study of anatomy, A. vulgaris has an anomocytic type of stomata and its distribution is mostly on the ventral part of the leaves. Through the BLAST process and phylogenetic tree reconstruction, the plant sequences being studied are closely related to several species of the genus Artemisia as indicated by a percentage identity above 98% and branch proximity between taxa in the reconstructed phylogenetic tree. Resumo Artemisia vulgaris L., pertencente à família Asteraceae, é uma planta herbácea com diversos benefícios à área médica. E para que seu uso na área médica possa ser explorado de forma otimizada, a planta deve ser minuciosamente identificada. Este estudo tem como objetivo identificar A. vulgaris por meio de análise morfoanatomia descritiva, quanto de código de barras do DNA utilizando BLAST e reconstrução de árvore filogenética. As características morfoanatômica foram observadas na raiz, caule e folha. A análise do código de barras do DNA foi realizada através da amplificação e alinhamento dos genes rbcL e matK. Todos os estudos foram feitos em três amostras de Taman Husada (Jardim de Plantas Medicinais) Graha Famili, Surabaya, Indonésia. A lâmina anatômica foi preparada pelo método da parafina. Estudos morfológicos revelaram que as folhas de A. vulgaris, tanto na parte média inferior quanto na parte superior do caule, apresentam diferenças, principalmente nos caracteres das estípulas, pecíolos e incisões. Já o estudo da anatomia revelou que A. vulgaris possui estômatos do tipo anomocítico e sua distribuição é principalmente na parte ventral das folhas. Através do processo BLAST e da reconstrução da árvore filogenética, as sequências de plantas em estudo apresentam estreira relação com várias espécies do gênero Artemisia, conforme indicado por uma identidade percentual acima de 98% e proximidade de ramos entre táxons na árvore filogenética reconstruída.