Phylogenetic Position Research Articles

The complete chloroplast genome of Rhododendronambiguum and comparative genomics of related species.

Rhododendron Linnaeus, 1753, the largest genus of woody plants in the Northern Hemisphere, includes some of the most significant species in horticulture. Rhododendronambiguum Hemsl, 1911, a member of subsection Triflora Sleumer 1947, exemplifies typical alpine Rhododendron species. The analysis of the complete chloroplast genome of R.ambiguum offers new insights into the evolution of Rhododendron species and enhances the resolution of phylogenetic relationships. This genome is composed of 207,478 base pairs, including a pair of inverted repeats (IRs) of 47,249 bp each, separated by a large single-copy (LSC) region of 110,367 bp and a small single-copy (SSC) region of 2,613 bp. It contains 110 genes: 77 protein-coding genes, 29 tRNAs, four unique rRNAs (4.5S, 5S, 16S, and 23S), with 16 genes duplicated in the IRs. Comparative analyses reveal substantial diversity in the Rhododendron chloroplast genome structures, identifying a fourth variant pattern. Specifically, four highly divergent regions (trnI-rpoB, ndhE-psaC, rpl32-ndhF, rrn16S-trnI) were noted in the intergenic spacers. Additionally, 76 simple sequence repeats were identified. Positive selection signals were detected in four genes (cemA, rps4, rpl16, and rpl14), evidenced by high Ka/Ks ratios. Phylogenetic reconstruction based on two datasets (shared protein-coding genes and complete chloroplast genomes) suggests that R.ambiguum is closely related to R.concinnum Hemsley, 1889. However, the phylogenetic positions of subsection Triflora Pojarkova, 1952 species remain unresolved, indicating that the use of complete chloroplast genomes for phylogenetic research in Rhododendron requires careful consideration. Overall, our findings provide valuable genetic information that will enhance understanding of the evolution, molecular biology, and genetic improvement of Rhododendron spieces.

Survey of trematodes in Manila clam Ruditapes philippinarum on the west coast of Korea: A preliminary study

The Manila clam Ruditapes philippinarum on the west coast of Korea harbors several digenetic trematodes. However, most studies in this region have been restricted to a few sampling sites and the current species designation of some trematodes is largely based on morphology, leaving the molecular phylogenetic position among the Digenea unsolved. Thus, we first provide both morphology and molecular phylogeny of some components in the trematodes community in the Manila clam based on a large-scale survey of 26 sites on the west coast, where well-developed tidal flats serve as large commercial clam culture beds. Our study revealed that the trematodes community in the clams consisted of at least 5 species that belong to 3 families (Himasthlidae, Gymnophallidae, Baccigeridae) and 1 superfamily (Monorchioidea). The life mode of the 5 different species included the metacercaria and sporocyst, with one species (Parvatrema duboisi) utilizing the clams as both the first and/or second intermediate host. Trematode infection prevalences were not evenly distributed among the study sites, although the reasons behind this are yet to be determined. Morphological identification was confirmed with the molecular analyses based on ITS and 28S rDNA; phylogenetic analysis also revealed that Cercaria pectinata infecting the clam gonad should be referred to as Bacciger bacciger hereafter. The present preliminary study provides a crucial baseline that could be further developed in a future study on the digenean trematodes community in the Manila clam.

The plastome and phylogenetic status of Cotoneaster rosiflorus (Rosaceae)

Endemic to Taiwan Province, China, Cotoneaster rosiflorus Kun-Cheng Chang & Fu-Yuan Lu 2011 (Rosaceae) holds significant ecological and ornamental importance. Despite its value, research on its molecular data and phylogenetic position has remained limited. In this study, we addressed this gap by sequencing the genome-skimming data, assembling its plastome, and investigating its phylogenetic position. The plastome, spanning 159,449 bp in length, consisted of a large single-copy (87,433 bp), a small single-copy (19,262 bp), and two inverted repeat regions (26,377 bp). We annotated a total of 128 functional genes, including 84 protein-coding genes, 36 transfer genes, and eight ribosomal RNA genes. The phylogenetic results indicated that C. rosiflorus is closely related to C. dammerii, suggesting that C. rosiflorus might have captured its chloroplast from C. dammerii through hybridization and introgression events. This study offered valuable insights for forthcoming phylogenetic and population genetic investigations of Cotoneaster.

The complete mitochondrial genome and phylogenetic analysis of Cyanopterus ninghais (Hymenoptera: Braconidae)

Cyanopterus ninghais is an important gregarious ectoparasitoid during the larval stage of Monochamus alternatus, a key vector for pine wilt disease in Asia. In this study, the complete mitochondrial genome of C. ninghais was sequenced and analyzed. The mitochondrial genome of C. ninghais is 15,386 bp in length, comprising 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), and 2 ribosomal RNA genes (rRNAs). The nucleotide composition is 41.32% A, 8.29% G, 6.06% C, and 44.33% T. Phylogenetic trees of Braconidae were constructed using 13 PCG sequences via Bayesian inference (BI) and maximum likelihood (ML) analyses to determine their phylogenetic position. Both ML and BI analyses revealed that C. ninghais is closely related to Euurobracon yokahamae, Virgulibracon endoxylaphagus, and Habrobracon hebetor.

The Possible Earliest Allopolyploidization in Tracheophytes Revealed by Phylotranscriptomics and Morphology of Selaginellaceae.

Selaginellaceae, originated in the Carboniferous and survived the Permian-Triassic mass extinction, is the largest family of lycophyte, which is sister to other tracheophytes. It stands out from tracheophytes by exhibiting extraordinary habitat diversity and lacking polyploidization. The organelle genome-based phylogenies confirmed the monophyly of Selaginella, with six or seven subgenera grouped into two superclades, but the phylogenetic positions of the enigmatic Selaginella sanguinolenta clade remained problematic. Here, we conducted a phylogenomic study on Selaginellaceae utilizing large-scale nuclear gene data from RNA-seq to elucidate the phylogeny and explore the causes of the phylogenetic incongruence of the S. sanguinolenta clade. Our phylogenetic analyses resolved three different positions of the S. sanguinolenta clade, which were supported by the sorted three nuclear gene sets, respectively. The results from the gene flow test, species network inference, and plastome-based phylogeny congruently suggested a probable hybrid origin of the S. sanguinolenta clade involving each common ancestor of the two superclades in Selaginellaceae. The hybrid hypothesis is corroborated by the evidence from rhizophore morphology and spore micromorphology. The chromosome observation and Ks distributions further suggested hybridization accompanied by polyploidization. Divergence time estimation based on independent datasets from nuclear gene sets and plastid genome data congruently inferred that allopolyploidization occurred in the Early Triassic. To our best knowledge, the allopolyploidization in the Mesozoic reported here represents the earliest record of tracheophytes. Our study revealed a unique triad of phylogenetic positions for a hybrid-originated group with comprehensive evidence and proposed a hypothesis for retaining both parental alleles through gene conversion.

The first complete mitochondrial genome of the genus Homoderus and insights into phylogeny of Lucanidae (Coleoptera: Lucanidae)

Homoderus mellyi belongs to the Lucanidae family of Coleoptera. The first complete mitogenome of Homoderus is reported in this paper. The genome is 16,807 bp in length and contains the typical 37 genes with 22 transfer RNA genes, 13 protein coding genes, and 2 ribosomal RNA genes. The gene order is conserved across the lineage. The average base composition of the mitogenome is 36.6% for A, 20.8% for C, 11.6% for G, and 31.1% for T. The percentage of GC is 32.3%. The genome organization, nucleotide composition, and codon usage are similar to other beetles. Phylogenetic analysis shows that Lucanidae is monophyletic, and all subfamilies are monophyletic, respectively. The phylogenetic position of H. mellyi is consistent with other research.

The complete chloroplast genome of Pyankovia brachiata (amaranthaceae), an annual desert plant in China

Pyankovia brachiata (Pall.) Akhani & Roalson 2007, is an annual plant belonging to the genus Pyankovia, family Amaranthaceae, which is widely distributed in the inland deserts of Northwest China. P. brachiata was previously categorized under the genus Salsola in Salsoleae and has been a long-standing topic of debate. Therefore, the complete chloroplast genome of P. brachiata must be studied to provide a theoretical reference for species classification. In this study, we sequenced P. brachiata samples and determined the species’ complete chloroplast genome. The complete chloroplast genome was 149,922 bp in length, with one large single copy (LSC: 83,565 bp), one small single copy (SSC: 18,535 bp), and two inverted repeat regions (IRa and IRb, 23,911 bp each). It contains 132 genes, including 87 protein-coding, eight rRNA, and 37 tRNA genes. The phylogenetic position showed that P. brachiata has the closest relationship with Caroxylon passerinum (accession number: NC057191.1). This study will provide genetic information and be beneficial to understanding the systematic position of P. brachiata within the Amaranthaceae.

Cranial anatomy of the Triassic rhynchosaur Mesosuchus browni based on computed tomography, with a discussion of the vomeronasal system and its deep history in Reptilia

Abstract The stem lineage of Archosauria is populated by a diverse fossil record that remains notably understudied relative to the crown clade. Prominent among these specimens is a beautifully preserved skull of the early mid-Triassic rhynchosaur Mesosuchus browni [Iziko South African Museum (SAM) 6536], whose phylogenetic position has considerable influence on patterns of pan-archosaurian cranial evolution. We used high-resolution, micro-computed tomography to re-examine the anatomy of this specimen, building on previous studies that were either limited to external observations or restricted to the braincase. A digital segmentation of the cranial elements and primary neurovascular canals of SAM-PK-6536 allows for expanded character scoring and constitutes a foundation for future comparative insights. Our data support the phylogenetically oldest instance of a pneumatized maxilla in a pan-archosaur, bringing the record of antorbital pneumatization into closer alignment with that of the neurocranium. The nasal cavity and primary palate of Mesosuchus includes a complex septomaxilla, a novel element anterior to the vomer, and is likely to have supported a well-developed vomeronasal system. The evolution of this system is discussed in terms of both phylogenetic pattern and how the skeletal architecture of Mesosuchus and other fossils could inform the signalling dynamics that pattern the vomeronasal system during development.

Diversity analysis of cyanobacterial flora from the Tatapani Hot Spring of Chhattisgarh and exploration of their industrially as well as environmentally valuable properties

The present study investigates the cyanobacterial diversity of Tatapani hot spring, Chhattisgarh, India, using a polyphasic approach, their pigment system, biofuel properties and ability to bioremediate emerging pollutant triclosan. While the microscopic analyses of the natural samples reflected high cyanobacterial diversity with all morpho-forms, physicochemical studies revealed temperature being the major factor affecting the cyanobacterial distribution in the hot spring. Among the 22 collected cyanobacterial samples, 14 were grown successfully under laboratory conditions and 10 of them showed optimum growth at 45 °C. However, four strains displayed preference for lower temperature (27 °C) for optimum growth. The polyphasic characterization of 14 strains revealed that all the thermophiles belonged to the genus Mastigocladus whereas the strains Sytonema sp. TPJ-3, Calothrix sp. TPB-2, Westiellopsis sp. TPR-29 and Desikacharya sp. TPB-4 constituted the group of mesophiles. Calothrix sp. TPB-2 was identified as a novel genus (Neocalothrix thermalis) based on distinct morphology and phylogenetic position with unique ITS folding pattern. Additionally, our study disclosed the production of comparatively higher amounts of pigments and medium chain length fatty acids (C16 to C18) by the thermophilic strains, which indicated their potential to be used as feedstocks for pigments and biofuel production respectively. Although the triclosan bioremediation study reflected considerable triclosan removal efficiencies of all the strains, most impressive results were observed in case of Westiellopsis sp. TPR-29 (93.08 %) and Mastigocladus sp. TA-8 (91.92 %). Moreover, the in-silico study-based revelation of high triclosan binding ability of cyanobacterial laccase (−5.8 and − 5.4 kcal/mol) and catechol 2,3-dioxygenase (−5.9 and − 6.0 kcal/mol) suggested the probable triclosan degrading potential of Westiellopsis and Mastigocladus. Conclusively, the Tatapani hot spring represents a unique environment with the dominance of true-branched heterocytous thermophilic cyanobacteria that have enormous potential to remove triclosan and produce high amounts of pigments and medium chain length fatty acids.

Annelid methylomes reveal ancestral developmental and aging-associated epigenetic erosion across Bilateria

BackgroundDNA methylation in the form of 5-methylcytosine (5mC) is the most abundant base modification in animals. However, 5mC levels vary widely across taxa. While vertebrate genomes are hypermethylated, in most invertebrates, 5mC concentrates on constantly and highly transcribed genes (gene body methylation; GbM) and, in some species, on transposable elements (TEs), a pattern known as “mosaic”. Yet, the role and developmental dynamics of 5mC and how these explain interspecies differences in DNA methylation patterns remain poorly understood, especially in Spiralia, a large clade of invertebrates comprising nearly half of the animal phyla.ResultsHere, we generate base-resolution methylomes for three species with distinct genomic features and phylogenetic positions in Annelida, a major spiralian phylum. All possible 5mC patterns occur in annelids, from typical invertebrate intermediate levels in a mosaic distribution to hypermethylation and methylation loss. GbM is common to annelids with 5mC, and methylation differences across species are explained by taxon-specific transcriptional dynamics or the presence of intronic TEs. Notably, the link between GbM and transcription decays during development, alongside a gradual and global, age-dependent demethylation in adult stages. Additionally, reducing 5mC levels with cytidine analogs during early development impairs normal embryogenesis and reactivates TEs in the annelid Owenia fusiformis.ConclusionsOur study indicates that global epigenetic erosion during development and aging is an ancestral feature of bilateral animals. However, the tight link between transcription and gene body methylation is likely more important in early embryonic stages, and 5mC-mediated TE silencing probably emerged convergently across animal lineages.

A feather star is born: embryonic development and nervous system organization in the crinoid Antedon mediterranea.

Crinoids belong to the Echinodermata, marine invertebrates with a highly derived adult pentaradial body plan. As the sister group to all other extant echinoderms, crinoids occupy a key phylogenetic position to explore the evolutionary history of the whole phylum. However, their development remains understudied compared with that of other echinoderms. Therefore, the aim here was to establish the Mediterranean feather star (Antedon mediterranea) as an experimental system for developmental biology. We first set up a method for culturing embryos in vitro and defined a standardized staging system for this species. We then optimized protocols to characterize the morphological and molecular development of the main structures of the feather star body plan. Focusing on the nervous system, we showed that the larval apical organ includes serotonergic, GABAergic and glutamatergic neurons, which develop within a conserved anterior molecular signature. We described the composition of the early post-metamorphic nervous system and revealed that it has an anterior signature. These results further our knowledge on crinoid development and provide new techniques to investigate feather star embryogenesis. This will pave the way for the inclusion of crinoids in comparative studies addressing the origin of the echinoderm body plan and the evolutionary diversification of deuterostomes.

Comparative structure and evolution of the organellar genomes of Padina usoehtunii (Dictyotales) with the brown algal crown radiation clade

BackgroundOrganellar genomes have become increasingly essential for studying genetic diversity, phylogenetics, and evolutionary histories of seaweeds. The order Dictyotales (Dictyotophycidae), a highly diverse lineage within the Phaeophyceae, is long-term characterized by a scarcity of organellar genome datasets compared to orders of the brown algal crown radiation (Fucophycidae).ResultsWe sequenced the organellar genomes of Padina usoehtunii, a representative of the order Dictyotales, to investigate the structural and evolutionary differences by comparing to five other major brown algal orders. Our results confirmed previously reported findings that the rate of structural rearrangements in chloroplast genomes is higher than that in mitochondria, whereas mitochondrial sequences exhibited a higher substitution rate compared to chloroplasts. Such evolutionary patterns contrast with land plants and green algae. The expansion and contraction of the inverted repeat (IR) region in the chloroplast correlated with the changes in the number of boundary genes. Specifically, the size of the IR region influenced the position of the boundary gene rpl21, with complete rpl21 genes found within the IR region in Dictyotales, Sphacelariales and Ectocarpales, while the rpl21 genes in Desmarestiales, Fucales, and Laminariales span both the IR and short single copy (SSC) regions. The absence of the rbcR gene in the Dictyotales may indicate an endosymbiotic transfer from the chloroplast to the nuclear genome. Inversion of the SSC region occurred at least twice in brown algae. Once in a lineage only represented by the Ectocarpales in the present study and once in a lineage only represented by the Fucales. Photosystem genes in the chloroplasts experienced the strongest signature of purifying selection, while ribosomal protein genes in both chloroplasts and mitochondria underwent a potential weak purifying selection.ConclusionsVariations in chloroplast genome structure among different brown algal orders are evolutionarily linked to their phylogenetic positions in the Phaeophyceae tree. Chloroplast genomes harbor more structural rearrangements than the mitochondria, despite mitochondrial genes exhibiting faster mutation rates. The position and the change in the number of boundary genes likely shaped the IR regions in the chloroplast, and the produced structural variability is important mechanistically to create gene diversity in brown algal chloroplast.

Complete mitochondrial genome of the edible mushroom Singerocybe alboinfundibuliformis (Clitocybaceae, Agaricales)

Singerocybe alboinfundibuliformis (Seok et al.) Yang, Qin & Takah 2014 is an edible mushroom distributed in several East or Southeast Asian countries. Herein, we report the mitochondrial genome of S. alboinfundibuliformis based on Illumina sequencing data. The overall length of the mitochondrial genome is 64,279 bp, with a GC content of 29.0%. It contains 14 typical protein-coding genes, 27 tRNA genes, two rRNA genes, and 13 intergenic ORFs. Most of these genes (39 out of 56) are transcribed at the forward strand, and few (17 out of 56) are transcribed at the reverse strand. Among these genes, only the rnl gene is invaded by an intron, and all other genes are intron-free. Phylogenetic analysis based on mitochondrial amino acid sequences supports the phylogenetic position of S. alboinfundibuliformis in Clitocybaceae, being close to Lepista sordida (Schumach.) Singer 1951. This study serves as a springboard for future investigation on fungal evolution in Clitocybaceae.

Schistura sonarengaensis, a new species of cave-dwelling loach (Teleostei: Nemacheilidae) from Meghalaya, northeast India.

A new species of nemacheilid loach, Schistura sonarengaensis sp. nov., is described from three cave-dwelling populations (Barak-Surma-Meghna drainage) in the South Garo Hills district of Meghalaya, India. The new species possesses prominent eyes but is easily distinguished from all the congeners of the genus Schistura from Barak-Surma-Meghna and adjacent rivers drainages of northeast Indian (except S. syngkai) in having 13-26 vertically elongated to circular mid-lateral black blotches (brownish in life) overlayered on a grayish-black mid-lateral stripe on a dull white or pale-beige (golden brown in life) body. However, it can be easily distinguished from S. syngkai in having a complete (vs. incomplete) lateral line with more 72-89 (vs. 19-42) lateral-line pored scales, greater pre-dorsal length (48.5-53.1 vs. 41.9-44.1 %SL), a wider body at dorsal-fin origin (11.3-16.7 vs. 9.4-10.3 %SL), greater dorsal (18.1-21.1 vs. 15.1-17.0 %SL) and lateral (20.9-24.1 vs. 17.4-18.9 %SL) head length, a wider head (14.5-18.5 vs. 11.6-13.3 %SL), and moderately forked (vs. emarginated) caudal fin. Further, molecular analysis confirms the distinctiveness of S. sonarengaensis sp. nov. from its congeners found in northeast India by significant divergences with uncorrected genetic distance ranging from 3.7% to 17.3% in the mitochondrial cytochrome c oxidase subunit I (COI) gene dataset. The phylogenetic position of the new species with its sister species was evaluated using maximum likelihood and Bayesian analysis. The species delimitation approaches assemble species by automatic partitioning (ASAP) and Poisson tree processes (PTP) utilized for testing species assignments consistently identified our test group as a distinct species from its sister species. Although the new species lacks typical morphological adaptations usually associated with a subterranean life, such as complete absence (or vestigial presence) of eyes and pigmentation, it exhibits a reduction of pigmentation when compared to the epigean congeners.

Genomics and phylogenetic relationships of microsporidia and their relatives.

Microsporidia are intracellular parasites that all possess a unique infection apparatus involving a polar tube. Upon contact with a host cell, this tube forms the conduit through which the parasite enters the host. Infecting mostly animals, microsporidian species can be transmitted vertically or horizontally, and exert various effects on their hosts: infections range from being relatively benign to lethal. Microsporidian genomes possess highly divergent sequences and are often substantially reduced in size. Their divergent sequences and unique morphology created early challenges to our understanding of their phylogenetic position within the tree of eukaryotes. Over the last couple of decades, advances in both sequencing technology and phylogenetic methodology supported a clear relationship between microsporidia and fungi. However, the specifics of this relationship were muddied by the lack of known microsporidian relatives. With increased taxon discovery and the morphological and molecular characterization of microsporidia-like taxa, rozellids and aphelids, a better resolved picture is emerging. Here we review the history of microsporidian taxonomy and current status of genomics of microsporidia and their nearest relatives, with an aim to understand their morphological and metabolic differences, along with their evolutionary relationships.

Early Cretaceous troodontine troodontid (Dinosauria: Theropoda) from the Ohyamashimo Formation of Japan reveals the early evolution of Troodontinae

A new troodontid dinosaur, Hypnovenator matsubaraetoheorum gen. et sp. nov., is described based on an articulated postcranial skeleton recovered from the fluvial deposits of the Albian Ohyamashimo Formation of the Sasayama Group in Tambasasayama City, Hyogo Prefecture, Japan. Hypnovenator is distinguished from other troodontids by four autapomorphies and a combination of additional features. Our phylogenetic analysis positions Hypnovenator as the oldest and one of the most basal troodontines, forming a clade with Gobivenator mongoliensis. The discovery of Hypnovenator suggests that small-bodied maniraptorans with a sleeping posture were common not only in environments with volcanic and eolian events or alluvial systems but also in fluvial systems. Geometric morphometric analysis of manual ungual phalanges shows that manual ungual phalanges I and III of Hypnovenator exhibit considerable morphological variation but are functionally similar, which differs from those of non-troodontine troodontids, reflecting the transition of manual motion within Troodontinae. Hypnovenator also has mosaic features in the pes related to cursoriality. This study reveals that asymmetrical arctometatarsus occurred by the Albian, and some morphological changes, such as shorter digit IV than digit III and non-ungual phalanges of digits III with roller joints and digit IV with weakly ginglymoid articulation, arose during the early Late Cretaceous.

A typical coastal plain taxon in central Brazil: Relationships and description of a new species of non-annual killifish (Cyprinodontiformes; Rivulidae) from the Paraná River basin

We describe a new species of the genus Atlantirivulus from a small first-order stream on the right margin of the Paraná River basin in the Mato Grosso do Sul, Brazil. The region of occurrence of the new species is known to be a hotspot for Melanorivulus species. This area, however, is approximately 700 km away from the record of occurrence of its closest congeners, which are distributed along the Brazilian coast in different hydrographic basins. Atlantirivulus enigmaticus, new species, is distinguished from all congeners by it s unique coloration, which consists of the flank being purplish grey with light green iridescence with brownish red dots scattered along of the body, by the neuromasts of the infraorbital series being aligned around eye, and by the presence of the short ventral process of the posttemporal. The phylogenetic position of the new species within the Atlantirivulus genus was based on molecular phylogenetic analysis using sequences of the mitochondrial gene cytochrome oxidase subunit 1. The results show that the new species is closely related to Atlantirivulus luelingi from the coastal drainages of the Brazilian state Santa Catarina. The phylogenetic position of the new species among congeners endemic to coastal river basins may be related to ancestral connections between coastal drainages and the Paraná River basin. The new species constitutes the westernmost record for the genus, and the first record of Atlantirivulus in the Paraná River basin. Insufficient collection efforts in areas of potential occurrence for the group and extinction processes in the broad region between the locality of the new species and the distribution areas of the remaining species may be a possible explanation for this disjunct distribution.

Complete chloroplast genomes of two Ainsliaea species and the phylogenetic analysis in the tribe Pertyeae.

The genus Ainsliaea DC. is one of the major groups within the tribe Pertyeae (Asteraceae). It comprises several important Chinese medicinal species. However, the phylogenetic position has undergone a long process of exploration. The complete chloroplast (cp) genome sequences data has not been employed in species identification and phylogeny of Ainsliaea. In this study, the complete cp genomes of two Ainsliaea species (A. gracilis and A. henryi) were reported, followed by structural, comparative, and phylogenetic analyses within the tribe Peryteae. Both cp genomes displayed a typical quadripartite circular structure, with the LSC and SSC regions separated by the IR regions. The genomes were 152,959 (A. gracilis) and 152,805 (A. henryi) base pairs (bp) long, with a GC content of 37.6%. They were highly conserved, containing 134 genes, including 87 protein-coding genes, 37 tRNA genes, 8 rRNA genes, and 2 pseudogenes (rps19 and ycf1). Moreover, thirteen highly polymorphic regions (e.g., trnK-UUU, trnG-UCC, trnT-GGU, accD-psaI, and rpl22-rps19) were identified, indicating their potential as DNA barcodes. The phylogenetic analysis confirmed the placement of Ainsliaea in the tribe Pertyeae, revealing close relationships with the genera Myripnois and Pertya. In comparison with Ainsliaea, Myripnois was more closely related to Pertya. This study lays a theoretical foundation for future research on species identification, population genetics, resource conservation, and sustainable utilization within Ainsliaea and Pertyeae.

Molecular identification of Mymarothecium viatorum and Anacanthorus penilabiatus in extensive native fish farming systems of the Peruvian Amazon

Piaractus brachypomus (Pacú) is the main native fish species cultivated in Peru and holds great potential for growth in aquaculture from the Peruvian Amazon. Between October 2021 and January 2022 in two fish producing farms in the Amazon region of San Martín in Peru, P. brachypomus individuals were examined for parasite evaluation. A total of 6366 monogeneans were isolated from the gills of 30 fish, revealing a prevalence of 100%, with an abundance and mean intensity of 212 parasites per fish. Monogeneans were morphologically identified as Mymarothecium viatorum and Anacanthorus penilabiatus. The genetic divergence in the 28S rDNA gene found among A. penilabiatus sequences was 0.1% and among Anacanthorus spp. it ranged from 0.9% to 7.5%. The genetic divergence found among the M. viatorum sequences was 0.3%. These finding represents the first molecular data of M. viatorum and A. penilabiatus in Peru using the 28S rDNA gene of these monogeneans. The new sequences obtained will contribute to future studies on the phylogenetic relationships among dactylogyrids. However, further research with a broader range of host-parasite samples and additional genetic markers is needed to clarify these relationships and provide stronger support for the phylogenetic positions.

Isolated, neglected, and likely threatened: a new species of Magoniella (Polygonaceae) from the seasonally dry tropical forests of Northern Colombia and Venezuela revealed from nuclear, plastid, and morphological data.

Seasonally tropical dry forests (SDTFs) in the American tropics are a highly diverse yet poorly understood and endangered ecosystem scattered from Northern Mexico to Southern Argentina. One floristic element of the STDFs is the genus Magoniella (Polygonaceae), which includes two liana species, M. laurifolia and M. obidensis, which have winged fruits and are distributed from Costa Rica to Southern Brazil. In a field expedition to the SDTFs of the Colombian Caribbean in 2015, morphologically distinctive individuals of Magoniella were found. In this study, we investigated the species boundaries within Magoniella and determined the phylogenetic position of these morphologically distinctive individuals in the tribe Triplaridae. We compiled morphological trait data across 19 specimens of both species and produced newly sequenced nuclear-plastid DNA data for M. obidensis. Morphometric analyses revealed significant differences in fruit length and perianth size among individuals from the Colombian Caribbean compared to M. obidensis and bract length when compared to M. laurifolia. Maximum likelihood analysis of non-conflicting nuclear and plastid datasets placed the Colombian Caribbean individuals as sister to M. obidensis with maximum statistical support. Additionally, pairwise sequence comparisons of the nuclear ribosomal ITS and the lfy2i loci consistently showed 15-point mutations (10 transitions, five transversions) and six 2 bp-long substitutions that differ between M. obidensis and the Colombian Caribbean individuals. Our morphological and molecular evidence thus suggests that the Colombian Caribbean individuals of Magoniella represent a divergent population from M. laurifolia and M. obidensis, which we describe and illustrate as a new species, M. chersina. Additionally, we provide nomenclatural updates for M. laurifolia and M. obidensis. This study highlights the power of combining morphological and molecular evidence in documenting and naming plant diversity.