Search Results (116)

Quercus petraea subsp. pinnatiloba is a narrowly distributed oak taxon in southeastern Türkiye, and its taxonomic position has long remained uncertain. This study aims to clarify its distinctiveness by integrating morphological, molecular, and biogeographical evidence. Principal Component Analysis (PCA) and Stepwise Discriminant Analysis (SDA) of 14 leaf traits revealed that subsp. pinnatiloba constitutes a morphologically stable and distinctly differentiated group from other Q. petraea subspecies and closely related taxa, characterized by key diagnostic traits such as petiole length (PL), lamina length (LL), length of leaf blade at its broadest point (WP), and lobe width at the tip of the widest lobe (LW). Phylogenetic analyses based on nuclear ITS and plastid markers (rbcL, psbA-trnH) confirmed its placement within sect. Quercus, yet consistently distinguished it genetically from other subspecies for the first time. Molecular dating (BEAST) suggested divergence in the Miocene (11 Mya with 95% HPD 3.01, 20.95) while RASP biogeographical analysis indicated an origin in the Euro-Siberian region with later dispersal into the Mediterranean. These integrative results support its recognition at species rank as Quercus pinnatiloba, clarifying its phylogenetic placement and underscoring the conservation importance of this lineage. Full article

In the traditional classification system of the Lauraceae family based on morphology and anatomy, the phylogenetic position of the genus Sassafras has long been controversial. Chloroplast (cp) evolution of Sassafras has not yet been illuminated. In this study, we first sequenced and assembled the complete cp genomes of Sassafras, and conducted the comparative cp genomics, phylogenomics, and divergence time estimation of this ecological and economic important genus. The whole length of cp genomes of the 10 Sassafras ranged from 151,970 bp to 154,011 bp with typical quadripartite structure, conserved gene arrangements and contents. Variations in length of cp were observed in the inverted repeat regions (IRs) and a relatively high usage frequency of codons ending with T/A was detected. Four hypervariable intergenic regions (ccsA-ndhD, trnH-psbA, rps15-ycf1, and petA-psbJ) and 672 cp microsatellites were identified for Sassafras. Phylogenetic analysis based on 106 cp genomes from 30 genera within the Lauraceae family demonstrated that Sassafras constituted a monophyletic clade and grouped a sister branch with the Cinnamomum sect. Camphora within the tribe Cinnamomeae. Divergence time between S. albidum and its East Asian siblings was estimated at the Middle Miocene (16.98 Mya), S. tzumu diverged from S. randaiense at the Pleistocene epoch (3.63 Mya). Combined with fossil evidence, our results further revealed the crucial role of the Bering Land Bridge and glacial refugia in the speciation and differentiation of Sassafras. Overall, our study clarified the evolution pattern of Sassafras cp genomes and elucidated the phylogenetic position and divergence time framework of Sassafras. Full article

Members of Sideritis sect. Empedoclia (Lamiaceae), known as ‘mountain tea’, are widely used medicinal plants. Their taxonomic classification is complex due to frequent hybridization and subtle morphological distinctions. This study examines 12 populations of eight native Sideritis taxa from Greece: S. clandestina subsp. clandestina, S. clandestina subsp. peloponnesiaca, S. euboea, S. raeseri subsp. raeseri, S. raeseri subsp. attica, S. scardica, S. sipylea, and S. syriaca subsp. syriaca. The objectives were to (1) monitor non-polar secondary metabolites (mainly terpenoids) using gas chromatography; (2) shed light on their phylogenetic relationships; (3) evaluate the correlation between genetic and chemical data. Diterpenes, particularly sideridiol, siderol, 7-epicandicandiol, and ent-3α,18-dihydroxy-kaur-16-ene, were the most abundant chemical compounds. Categorical Principal Component Analysis revealed that S. raeseri subsp. attica is chemically distinct, while the rest are grouped into two clusters: one comprising S. clandestina and S. sipylea, and the other including all the rest. Genetic analysis based on chloroplast DNA (matK, psbA-trnH, trnL-F), showed that S. sipylea and S. syriaca subsp. syriaca were the most phylogenetically distant groups. Our study enhances the understanding of Sideritis chemovariability and phylogeny, supporting also taxonomic, authentication, and breeding efforts. Full article

DNA barcoding of intraspecific diversity of agricultural crops is important to develop the genetic passports of valuable genotypes and cultivars. The advantage of DNA-barcoding as compared to traditional genotyping of cultivars is that the procedure can be unified and applied for the broad range of accessions. This not only makes it cost efficient, but also allows to develop open access genetic databases to accumulate information of the world’s germplasm collections of different crops. In this regard, the aim of the review was to analyze the latest research in this field, including the selection of loci, universal primers, strategies of amplicons analysis, bioinformatic tools, and the development of databases. We reviewed the advantages and disadvantages of each strategy with the focus of cultivars identification. The data indicates that following chloroplast loci are the most prominent for the intraspecific diversity analysis: (trnE-UUC/trnT-GUU, rpl23/rpl2.l, psbA-trnH, trnL-trnF, trnK, rpoC1, ycf1-a, rpl32-trnL, trnH-psbA and matK). We suggest that the combination of three or four of these loci can be a sufficient DNA barcode for cultivar-level identification. This combination has to be selected for each crop. Advantages and disadvantages of different approaches of amplicons analysis are discussed. The bioinformatic tools and databases for the plant barcoding are reviewed. This review will be useful for selecting appropriate strategies for barcoding of intraspecific diversity of agricultural crops to develop genetic passports of valuable cultivars in germplasm collections worldwide. Full article

Rhododendron purdomii Rehder & E. H. Wilson (Ericaceae) is a threatened ornamental and medicinal shrub or small tree species primarily distributed in the Qinling-Daba Mountains of Central China. To facilitate its conservation and utilization, the complete chloroplast genome of Rh. purdomii was sequenced, assembled, and characterized. The cp genome exhibited a typical quadripartite structure with a total length of 208,062 bp, comprising a large single copy (LSC) region of 110,618 bp, a small single copy (SSC) region of 2606 bp, and two inverted repeat (IR) regions of 47,419 bp each. The overall GC content was 35.81%. The genome contained 146 genes, including 96 protein-coding genes, 42 transfer RNA genes, and 8 ribosomal RNA genes. Structure analysis identified 67,354 codons, 96 long repetitive sequences, and 171 simple sequence repeats. Comparative genomic analysis across Rhododendron species revealed hypervariable coding regions (accD, rps9) and non-coding regions (trnK-UUU-ycf3, trnI-CAU-rpoB, trnT-GGU-accD, rpoA-psbL, rpl20-trnC-GCA, trnI-CAU-rrn16, and trnI-CAU-rps16), which may serve as potential molecular markers for genetic identification. Phylogenetic reconstruction confirmed the monophyly of Rhododendron species and highlighted a close relationship between Rh. purdomii and Rh. henanense subsp. lingbaoense. These results provide essential genomic resources for advancing taxonomic, evolutionary, conservation, and breeding studies of Rh. purdomii and other species within the genus Rhododendron. Full article

Salvia, a medicinally and economically important genus, is widely used in traditional medicine, agriculture, and horticulture. This study compares the chloroplast genomes of eight East Asian Salvia species to assess genetic diversity, structural features, and evolutionary relationships. Complete chloroplast genomes were sequenced, annotated, and analyzed for gene content, codon usage, and repetitive sequences. Phylogenetic relationships were reconstructed using Maximum Likelihood, Maximum Parsimony and Bayesian inference. The genomes exhibited a conserved quadripartite structure (151,081–152,678 bp, GC content 37.9–38.1%), containing 114 unique genes with consistent arrangement. Codon usage favored A/T endings, with leucine (Leu) most frequent and cysteine (Cys) least. We identified 281 long sequence repeats (LSRs) and 345 simple sequence repeats (SSRs), mostly in non-coding regions. Comparative analysis revealed five hypervariable regions (trnH-psbA, rbcL-accD, petA-psbJ, rpl32-trnL, ycf1) as potential molecular markers. Phylogenetic analysis confirmed the monophyly of East Asian Salvia, dividing them into five clades, with Sect. Sonchifoliae basal. While G1, G3, and G8 were monophyletic, G5 and G6 were paraphyletic, and the G7-G8 relationship challenged traditional classifications. The genomic evidence provides crucial insights for resolving long-standing taxonomic uncertainties and refining the classification system of Salvia. These findings suggest a complex evolutionary history involving hybridization and incomplete lineage sorting, providing valuable genomic insights for Salvia phylogeny, taxonomy, and conservation. Full article

Phylogenetic relationships within the subtribe Arethusinae (Arethuseae: Epidendroideae: Orchidaceae) remain unresolved, with particular uncertainty surrounding the phylogenetic positions of Anthogonium gracile and Eleorchis japonica. The monophyly of this subtribe remains contentious, making it one of the challenging taxa in Orchidaceae phylogenetics. In this study, we sequenced and analyzed the complete plastome sequences of A. gracile and E. japonica for the first time, aiming to elucidate their plastome characteristics and phylogenetic relationships. Both plastomes exhibited a conserved quadripartite structure, with 158,358 bp in A. gracile and 152,432 bp in E. japonica, and GC contents of 37.1% and 37.3%, respectively. Comparative analyses revealed strong structural conservation, but notable gene losses: E. japonica lacked seven ndh genes (ndhC/D/F/G/H/I/K), whereas A. gracile retained a complete ndh gene set. Repetitive sequence analysis identified an abundance of simple sequence repeats (68 and 77), tandem repeats (43 and 30), and long repeats (35 and 40). Codon usage displayed a bias toward the A/U termination, with leucine and isoleucine being the most frequent. Selection pressure analysis indicated that 68 protein-coding genes underwent purifying selection (Ka/Ks < 1), suggesting evolutionary conservation of plastome protein-coding genes. Nucleotide diversity analysis highlighted six hypervariable regions (rps8-rpl14, rps16-trnQ^UUG, psbB-psbT, trnT^UGU-trnL^UAA, trnF^GAA-ndhJ, and ycf1), suggesting their potential as molecular markers. Phylogenomic reconstruction, using complete plastome sequences, (ML, MP, and BI) indicated that Arethusinae was non-monophyletic. A. gracile formed a sister relationship with Mengzia foliosa and E. japonica, whereas Arundina graminifolia exhibited a sister relationship with Coelogyninae members. These results shed new light on the plastome characteristics and phylogenetic relationships of Arethusinae. Full article

Phlegmariurus, a diverse genus within the Lycopodiaceae family, has wide diversity in tropical regions, including Thailand. Accurate species delimitation in the tropical clubmoss genus Phlegmariurus is challenged by high morphological plasticity and genetic complexity. This study applied an integrative multilocus approach combining morphometric analysis of 27 complete specimens, 35 Phlegmariurus and one Lycopodiella accessions for AFLP genotyping (926 loci; PIC 0.32), SSR profiling (44 loci; PIC 0.57; expected heterozygosity 0.35), and chloroplast barcoding using rbcL (1308 bp; bootstrap 89–99%) and the psbA-trnH intergenic spacer (308 bp; bootstrap ≥ 94%). A total of 13 were identified as belonging to seven known species, including P. nummulariifolius (NST01, NST15, NST36), P. goebelii (JP04), P. phlegmaria (NST13), P. verticillatus (PHI16), P. squarrosus (NST21, NST22, MY31), P. tetrastichus (NST30), and P. carinatus (MY32, MY33, NST34). Morphological clustering and molecular markers consistently distinguished Phlegmariurus accessions from the Lycopodiella outgroup. Additionally, 19 previously unclassified Phlegmariurus accessions were successfully identified as belonging to the species P. nummulariifolius (NST23), P. goebelii (NST03, JP05, STN12, PNA14, SKA25, CPN26, KRB27, PNA28), P. phlegmaria (NWT07, STN08, NST09, NST10, PHI29), P. squarrosus (NST17), and P. carinatus (PNA06, STN18, CPN19, JP24). Moreover, this study identified three novel lineages (NST02, STN11, NST20) with strong support across datasets. The combination of broad genomic coverage (AFLP), fine-scale allelic resolution (SSR), deep-branch backbone (rbcL), and terminal-branch discrimination (psbA-trnH) yields a robust framework for species identification. These results define clear operational units for conservation prioritization and establish a foundation for marker-assisted development of ornamental Phlegmariurus cultivars. Full article

The taxonomic identification of plant species is traditionally based on morphological traits, the use of which may create difficulties in cases of close-related species showing great morphological variability. In such cases, the use of DNA markers for species identification and delimitation can be of great help. Himantoglossum W.D.J.Koch (Orchidaceae) is a genus with notable morphological variability, comprising the clade hircinum-caprinum (Himantoglossum s.s.) with nine taxa, from which H. jankae, H. hircinum, H. montis-tauri, H. caprinum and H. samariense have being reported in Greece. However, a previous morphological study of Himantoglossum s.s. from all over Greece could not verify the presence of these reported species, but of only one highly diverse taxon throughout the country. Here, we studied the genetic variation and differentiation of Himantoglossum s.s. populations from the entire distribution of the genus in Greece employing ISSR markers, to further elucidate the taxonomic status of Himantoglossum s.s. in Greece. High genetic variation was revealed, both in the populations of the “core” distribution and in the peripheral/marginal ones, pointing to their evolutionary potential. This variation is mainly attributed to differences within the populations and, to a lesser extent, among them. No differentiation of the populations proposed to belong to a different taxon was found and no species-specific markers were identified that may discriminate the above populations from the rest. In addition, two cpDNA and one nDNA fragments (accD, psbA-trnH and ITS2, respectively) were sequenced in a number of individuals representative of the whole dataset. All three fragments were conserved, showing restricted polymorphism and having no correlation to the populations or to the taxa of Himantoglossum s.s. in Greece. Overall, the high genetic variation of the populations of Himantoglossum s.s. in Greece, especially of the peripheral/marginal ones, is a valuable asset towards their conservation. Full article

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. Full article

This study addresses the phylogenetic relationships within the genus Dianthus in South Africa, employing a molecular analysis approach and the distribution pattern of the representatives of the genus. A robust phylogenetic tree comprising three plastids (trnH-psbA, trnK-matK, and trnK-psbA) and a nuclear region was assembled based on 94 taxa of Dianthus and Petrorhagia species using Mr Bayes analysis. Furthermore, distribution maps for each Dianthus species were generated using QGIS. Our results have revealed Dianthus as monophyletic when Petrorhagia is used as an outgroup. Four strongly supported clades were identified (Africa, Eurasian, Verruculosi and Armerium), indicating geographical distinctions. We identified potential discrepancies, notably in the placement of D. mooiensis and D. namaensis. An unexpected relationship between D. thunbergii and D. bolusii was also highlighted, which challenges current morphological classifications. Defined clades were further observed within African Dianthus (Ethiopian and Northern African species; BS/100, and Western and Eastern regions of South Africa; BS/100), while two subclades (BS/100 and BS/72) were observed within the South African clade. Additionally, ITS generated unsupported and unresolved trees independently, as with the three plastid markers (trnH-psbA, trnK-matK, and trnK-psbA). The identified clades and unresolved species placements warrant further investigation, possibly through additional molecular gene markers and broader taxon sampling. Full article

The genus Cymbidium, with its intricate floral elements, pronounced endemicity, and patchy distribution, evolves a rich diversity of morphological forms and a wide variety of species while causing an indistinctness in the classification of its species. To elucidate the phylogenetic relationships among Cymbidium species and enhance their taxonomic classification by DNA barcoding, this study conducted amplification and sequence results of nuclear (ITS) and chloroplast genes (matK, rbcL, trnL-F, psbA-trnH) with phenotypic genetic diversity analysis, genetic distance analysis, and phylogenetic analysis from 48 samples of Cymbidium species. The comparison of genetic distance variations showed that psbA-trnH, ITS + psbA-trnH, and ITS + matK + psbA-trnH exhibit minimal overlap and significant genetic variation within Cymbidium species. The phylogenetic analysis indicated that the combination, ITS + matK + psbA-trnH, has the highest identification rate. Notably, both the phylogenetic analysis and the genetic diversity analysis of phenotypic traits consistently indicated a clear divergence between epiphytic and terrestrial orchids, with epiphytic orchids forming a distinct clade. This provides reference evidence for studying the ecological adaptations and evolutionary differences between epiphytic and terrestrial orchids, as well as a scientific basis for the classification and identification, germplasm conservation, resource utilization, and phylogenetic evolution of orchids. Full article

This study focused on the in vitro propagation and DNA barcoding of the endangered herb Solanum corymbosum from the La Joya Desert, Peru. The primary objective of this study was to establish a protocol for the in vitro conservation and molecular identification of these species. This study used cytokinins, specifically BAP and TDZ, for shoot regeneration from leaf explants, achieving high rates of shoot regeneration and proliferation. The optimal concentration of TDZ (1 mg/L) resulted in 88.7% regeneration. In the rooting phase, auxins, specifically, IBA and NAA, were used, achieving high rooting rates and root numbers. The optimal concentration of IBA (2 mg/L) resulted in 100% rooting and 9.8 roots per shoot. DNA barcoding with four cpDNA markers (matK, rbcL, trnL-trnF, and psbA-trnH) allowed accurate molecular identification, confirming species identity within the genus Solanum. Key results included successful in vitro propagation with high rates of shoot formation and rooting and 100% survival during acclimatization. Molecular analysis confirmed the taxonomic identification of S. corymbosum, with high percentages of similarity (97% to 100%) with other Solanum species. Phylogenetic analysis confirmed its classification within the Radicans clade, sharing its characteristics with other Andean species of the genus Solanum. This study revealed that the propagation in vitro protocol and DNA barcoding are effective tools for the conservation of S. corymbosum, offering valuable methods for the conservation and genetic study of this and other threatened plant species. Full article

Phytoplasmas are a group of plant-pathogenic, cell-wall-less bacteria vectored primarily by leafhoppers (Hemiptera Cicadellidae), one of the most diverse families of insects. Despite the importance of documenting associations between phytoplasmas, their insect vectors, and plant hosts to prevent disease outbreaks, such knowledge is currently highly incomplete and largely neglects the diversity of the system in natural areas. Here, we used anchored hybrid enrichment (AHE) to recover the DNA of five plant genes (rbcL, matK, ITS1, ITS2, and trnH-psbA) in 58 phloem-feeding leafhoppers from around the world that had previously tested positive for phytoplasma infection. Using BLASTn and a strict filtering approach, we assigned taxonomic classifications to the plant sequences and tested for cophylogenetic signals between potential Deltocephalinae leafhopper vectors and their associated plants. We observed incongruence between plant and insect phylogenies. Many leafhopper species, including presumed grass specialists, fed on distantly related plant lineages; 66% of sampled leafhoppers fed on plants from at least two different orders. By disentangling phytoplasma–leafhopper–plant interactions, we identify locations at risk of phytoplasma disease outbreaks. Furthermore, the observed wide diet breadth raises questions about how phytoplasma infection may manipulate the feeding preference of their insect host and helps fill the gaps in understanding the ecology and diversification of the tripartite association. Full article

Synsepalum and Englerophytum are two closely related genera of the sub-family Chrysophylloideae in the family Sapotaceae. It has been reported that the two genera are a monophyletic group, and their generic limitations are uncertain. Synsepalum is an economically important genus that includes the medicinally and culinarily important plant, -miracle berry, S. dulcificum. The phylogenetic relationships among the species are poorly understood. This study has been conducted to refine the phylogenetic relationships between and within the two genera utilizing nuclear and chloroplast DNA data. Bayesian analyses and Maximum likelihood of nuclear internal transcribed spacer (ITS) and plastid (trnH-psbA) sequences were used to reconstruct the phylogeny of the two genera. Phylogenetic trees generated for both regions (nuclear and plastid) resulted in the resolution of six clades. Four of the clades correspond to species in the genus Synsepalum and two clades include species of Englerophytum. The two clades of Englerophytum are nested within Synsepalum suggesting that the two genera are closely related and may not merit their current circumscription as distinct genera. Also, Synsepalum is confirmed to constitute more than one lineage suggesting it is not monophyletic in its current definition. Overall, the study suggests the need for a comprehensive evaluation of all species currently recognized in the two genera. Full article