Molecular Phylogenetic Inference Research Articles

Synopsis of Calea subgen. Teucriifoliae (Asteraceae: Neurolaeneae), a new subgenus endemic to the Cerrado

Calea comprises 159 species characterized by striate phyllaries, pistillate ray florets, yellow corolla, and pappus elements as scales. The “Calea teucriifolia complex” is an informal group of 15 species. Molecular phylogenetic inference recognized the polyphyly of this group, but also supports the recognition of a monophyletic subgenus when considering a more restrict set of species. Thus, the aim of this study is to morphologically circumscribe the group at subgeneric rank and provide an updated nomenclatural and taxonomic synopsis. As defined here, C. subgen. Teucriifoliae comprises eight species (C. ferruginea, C. hymenolepis, C. hypericifolia, C. microphylla, C. ramosissima, C. senecioides, C. teucriifolia and C. villosa). The new subgenus is endemic to the Cerrado tropical savanna and is characterized by cylindrical involucres, reddish phyllaries, and pappus scales shorter than 1 mm. Seven lectotypes are designated and data on type specimens is clarified including localities, dates of collection, and collector. In addition, we record new state level occurrences for four species and provide a key for species identification.

Description and Characterization of the Odontella aurita OAOSH22, a Marine Diatom Rich in Eicosapentaenoic Acid and Fucoxanthin, Isolated from Osan Harbor, Korea.

Third-generation biomass production utilizing microalgae exhibits sustainable and environmentally friendly attributes, along with significant potential as a source of physiologically active compounds. However, the process of screening and localizing strains that are capable of producing high-value-added substances necessitates a significant amount of effort. In the present study, we have successfully isolated the indigenous marine diatom Odontella aurita OAOSH22 from the east coast of Korea. Afterwards, comprehensive analysis was conducted on its morphological, molecular, and biochemical characteristics. In addition, a series of experiments was conducted to analyze the effects of various environmental factors that should be considered during cultivation, such as water temperature, salinity, irradiance, and nutrients (particularly nitrate, silicate, phosphate, and iron). The morphological characteristics of the isolate were observed using optical and electron microscopes, and it exhibited features typical of O. aurita. Additionally, the molecular phylogenetic inference derived from the sequence of the small-subunit 18S rDNA confirmed the classification of the microalgal strain as O. aurita. This isolate has been confirmed to contain 7.1 mg g-1 dry cell weight (DCW) of fucoxanthin, a powerful antioxidant substance. In addition, this isolate contains 11.1 mg g-1 DCW of eicosapentaenoic acid (EPA), which is one of the nutritionally essential polyunsaturated fatty acids. Therefore, this indigenous isolate exhibits significant potential as a valuable source of bioactive substances for various bio-industrial applications.

Revision of Campylosiphon (Burmanniaceae), with New Combinations and a New Species Described

Abstract— Campylosiphon (Burmanniaceae), a genus with two fully mycoheterotrophic species distributed in the tropics of South America and West Africa, is extended to include two Asian species and one African species with “wingless” flowers. Specifically, Burmannia championii and B. densiflora are transferred to Campylosiphon, and a Campylosiphon species new to science is described from Guizhou, China, supported by a combination of morphological comparison and molecular phylogenetic inference. We reveal that the genus Campylosiphon can be characterized by five morphological aspects. With this revised circumscription, Campylosiphon becomes the third genus in Burmanniaceae with a pantropical distribution pattern. We also report that two Campylosiphon species have advanced degraded plastomes, losing all protein coding genes for photosynthesis.

DNA barcodes of Saudi Arabian birds: Implications for species identification and diversity analysis

ObjectivesDNA barcoding using cytochrome c oxidase I (COI) gene is an effective tool for species identification with additional power of measuring molecular diversity and phylogenetic inference. In this study, we evaluated the performance of COI gene sequences for species identification and molecular diversity analysis of some Saudi Arabian birds. MethodsWe sequenced the 694 base pair segment of COI gene from 5 samples of white cheeked bulbul (Pycnonotus leucogenys), 4 samples of black scrub robin (Cercotrichas podobe), and 2 samples of crested lark (Galerida cristata), all belonged to the same Order. We also included all the COI sequences available in the GenBank for these birds with the aim of studying molecular diversity across geographies. For species identification, we enriched our dataset by including COI barcodes of other Saudi Arabian bird species, including Arabian partridge (Alectoris melanocephala), houbara bustard (Chlamydotis undulata macqueenii), green bee-eater (Merops orientalis), laughing dove (Streptopelia senegalensis), namaqua dove (Oena capensis) and collared dove (Streptopelia decaocto), representing different genera. ResultsWhite-cheeked bulbul from Saudi Arabia showed more diversity than the same birds from Iraq. The mean nucleotide difference and nucleotide diversity were 5.20 and 0.009 respectively with as Tajima’s D score of 1.6549 indicating the scarcity of rare alleles. The specimens of black scrub robin from Saudi Arabia and Djibouti showed mixed phylogeny with only two segregating sties and a near zero Tajima’s D score indicating no major selection. Out of 18 samples of crested lark, 13 birds from 4 different geographical regions showed identical sequences, while 3 birds from Russia and 1 from Cyprus grouped in a separate cluster and 1 crusted lark from Djibouti differed from all. The mean nucleotide difference and nucleotide diversity were 0.6993 and 0.0014, while a negative Tajima’s D of −1.1956 indicated the presence of rare alleles. Phylogenetic analysis of 9 different species of Saudi Arabian birds showed the discriminatory power of COI barcodes as all the different species grouped separately in specific clusters. ConclusionsCOI barcodes are not only indispensable tools for species identification but can also be used for analyzing molecular diversity and phylogenetic inference.

Low-coverage whole genome sequencing of eleven species/subspecies in Dioscorea sect. Stenophora (Dioscoreaceae): comparative plastome analyses, molecular markers development and phylogenetic inference.

Dioscorea sect. Stenophora (Dioscoreaceae) comprises about 30 species that are distributed in the temperate and subtropical regions of the Northern Hemisphere. Despite being evolutionarily "primitive" and medically valuable, genomic resources and molecular studies of this section are still scarce. Here, we conducted low-coverage whole genome sequencing of 11 Stenophora species/subspecies to retrieve their plastome information (whole plastome characteristics, plastome-divergent hotspots, plastome-derived SSRs, etc.) and polymorphic nuclear SSRs, as well as performed comparative plastome and phylogenetic analyses within this section. The plastomes of Stenophora species/subspecies ranged from 153,691 bp (D. zingiberensis) to 154,149 bp (D. biformifolia) in length, and they all contained the same 114 unique genes. All these plastomes were highly conserved in gene structure, gene order and GC content, although variations at the IR/SC borders contributed to the whole length differences among them. The number of plastome-derived SSRs among Stenophora species/subspecies varied from 74 (D. futschauensis) to 93 (D. zingiberensis), with A/T found to be the most frequent one. Seven highly variable regions and 12 polymorphic nuclear SSRs were identified in this section, thereby providing important information for further taxonomical, phylogenetic and population genetic studies. Phylogenomic analyses based on whole plastome sequences and 80 common protein coding genes strongly supported D. biformifolia and D. banzhuana constituted the successive sister species to the remaining sampled species, which could be furtherly divided into three clades. Overall, this study provided a new perspective for plastome evolution of Stenophora, and proved the role of plastome phylogenomic in improving the phylogenetic resolution in this section. These results also provided an important reference for the protection and utilization of this economically important section.

Insights into the evolutionary history of Diestramimini cave crickets (Orthoptera, Rhaphidophoridae)

AbstractDiestramimini is one of the two tribes of Aemodogryllinae and is mainly distributed in southern China and Southeast Asia. The intergeneric phylogenetic relationship and historical biogeography of this tribe remain unclear. Here, we present the first phylogenetic and biogeographical analyses of Diestramimini based on three mitochondrial (COI, 12S rRNA and 16S rRNA) and two nuclear (18S rRNA and 28S rRNA) gene fragments. The molecular phylogenetic inference strongly supports the monophyly of Diestramimini and recovers the sister‐group relationship between Diestramima + Tamdaotettix and Arboramima + Gigantettix. A new genus, Bidiestramima Zhu & Shi gen. n., is established and recovered as sister to all the remaining genera of Diestramimini. Moreover, a new species Bidiestramima hekouensis Zhu & Shi gen. et sp. n. is described. Mimadiestra is recovered as paraphyletic, and thus, we propose two new combinations based on the combination of morphological and molecular evidence: Bidiestramima dicha comb. n. and Tamdaotettix (Laotettix) gracilus comb. n. Divergence time estimation and reconstruction of ancestral areas indicate that Diestramimini in China may have originated from Southern Yunnan and Guangxi during the mid‐Oligocene and had two separate evolutionary routes. The diversification of Diestramimini has been driven by several dispersal and vicariance events since the Miocene, linked to the uplift of the Himalaya–Tibetan Plateau, the formation of the monsoon and climate fluctuations.

Morphological and Molecular Description of Immature Southwellina hispida (Van Cleave, 1925) Witenberg, 1932 (Acanthocephala: Polymorphidae) from the Body Cavity of the Paratenic Host Gillichthys mirabilis Cooper (Gobiidae) in California, with Analyses of the Chemical Composition of Hooks and Spines.

Immature Southwellina hispida (Van Cleave, 1925) Witenberg, 1932 from the body cavity of the paratenic host Gillichthys mirabilis Cooper (Gobiidae) in California are described. New Scanning Electron images and features of micropores, hook and spine Gallium cut sections and chemistry using Energy Dispersive X-ray analysis (EDXA), and molecular profile are provided for the first time. The 18S rDNA and mt Cox1 sequences were performed for molecular and phylogenetic study. Our specimens were somewhat comparable to those reported from other paratenic hosts in Asia, Europe, and North and South America but varied in relative sizes of trunk and other structures, proboscis formula, and distribution of trunk spines. About 60 publications were reviewed of which one third included line drawings used for comparative morphometrics. In our specimens, the trunk measured 2.72-3.10mm long by 0.92-1.07mm wide and the proboscis 700-800 × 270-312μm had 20-21 rows of 14-15 hooks each measuring 47-55 long by 12-15μm wide at base anteriorly, 47-48 × 20-23μm at middle bulge, and 43-50 × 13-20μm basally. These measurements, among others were compared with measurements of juveniles from 13 other collections world-wide and intraspecific variability was noted especially in the shape of hook roots that were occasionally misinterpreted. EDXA showed hooks with high levels of Sulfur especially at the tip and edge of all hooks and low levels of Calcium and Phosphorus. Anterior spines had higher levels of Sodium but Gallium cut spine sections had higher levels of Calcium at middle and of Sulfur at base of spines. Micropores were variably distributed on the body wall and extended to the cortical layer of spines. Gene sequences of the 18S and the mitochondrial cytochrome c oxidase subunit 1 (cox 1) region were amplified for specimens of S. hispida. Molecular phylogenetic analysis inference from 18S rDNA and mt Cox1 gene sequences show a close relationship with previously reported myxozoan sequences available on GenBank database. Phylogenetic analysis positioned our S. hispida in a well-supported clade including other members of Polymorphidae. The present study combined morphological, morphometric and molecular data to identify S. hispida.

Morphology and molecular phylogeny of Pauciconfibuloides amazonica gen. n. sp. n. (Platyhelminthes, Monogenoidea) parasitizing the Amazonian croaker Plagioscion squamosissimus.

An integrative study was performed to understand the phylogenetic relationships of an undescribed, freshwater species of microcotylid parasitizing Plagioscion squamosissimus from the Amazon River Basin. Based on morphological and molecular analysis (18S rDNA and partial 28S rDNA genes), a new genus is proposed to accommodate this new species, Pauciconfibuloides amazonica gen. n. sp. n. The new genus is closely related to Protastomicrocotylinae and Pauciconfibula by sharing the vagina, male copulatory organ, and genital atrium all unarmed. However, Pauciconfibuloides gen. n. can be distinguished from those taxa by the prostatic system and position of the vaginal pore. Molecular phylogenetic inference suggests a sister relationship with species of Polylabris (Prostatomicrocotylinae), but to date, there are no available 18S or 28S rDNA sequences of Pauciconfibula to be compared. This is the first report of a microcotylid parasitizing a freshwater sciaenid from South America.

Comparative analysis of alignment-free genome clustering and whole genome alignment-based phylogenomic relationship of coronaviruses.

The SARS-CoV-2 is the third coronavirus in addition to SARS-CoV and MERS-CoV that causes severe respiratory syndrome in humans. All of them likely crossed the interspecific barrier between animals and humans and are of zoonotic origin, respectively. The origin and evolution of viruses and their phylogenetic relationships are of great importance for study of their pathogenicity and development of antiviral drugs and vaccines. The main objective of the presented study was to compare two methods for identifying relationships between coronavirus genomes: phylogenetic one based on the whole genome alignment followed by molecular phylogenetic tree inference and alignment-free clustering of triplet frequencies, respectively, using 69 coronavirus genomes selected from two public databases. Both approaches resulted in well-resolved robust classifications. In general, the clusters identified by the first approach were in good agreement with the classes identified by the second using K-means and the elastic map method, but not always, which still needs to be explained. Both approaches demonstrated also a significant divergence of genomes on a taxonomic level, but there was less correspondence between genomes regarding the types of diseases they caused, which may be due to the individual characteristics of the host. This research showed that alignment-free methods are efficient in combination with alignment-based methods. They have a significant advantage in computational complexity and provide valuable additional alternative information on the genomes relationships.

Diversity, phylogeny and evolution of the rapidly evolving genus Psidium L. (Myrtaceae, Myrteae).

Psidium is the fourthth largest genus of Myrtaceae in the Neotropics. Psidium guajava is widely cultivated in the tropics for its edible fruit. It is commercially under threat due to the disease guava decline. Psidium cattleyanum is one of the 100 most invasive organisms in the world. Knowledge of the phylogenetic relationships within Psidium is poor. We aim to provide a review of the biology, morphology and ecology of Psidium, a phylogenetic tree, an infrageneric classification and a list of species. Morphological and geographic data were obtained by studying Psidium in herbaria and in the field between 1988 and 2020. Forty-six herbaria were visited personally. A database of approx. 6000 specimens was constructed, and the literature was reviewed. Thirty species (about a third of the species in the genus) were sampled for molecular phylogenetic inference. Two chloroplast (psbA-trnH and ndhF) and two nuclear (external transcribed spacer and internal transcribed spacer) regions were targeted. Phylogenetic trees were constructed using maximum likelihood (ML; RaxML) and Bayesian inference (BI; MrBayes). Psidium is a monophyletic genus with four major clades recognized as sections. Section Psidium (ten species), to which P. guajava belongs, is sister to the rest of the genus; it is widespread across the Neotropics. Section Obversifolia (six species; restricted to the Brazilian Atlantic Forest), which includes P. cattleyanum, is sister to the innermost clade composed of sister sections Apertiflora (31 species; widespread but most diverse in the Brazilian Atlantic Forest) + Mitranthes (26 species; widespread in dry forests and probably diverse in the Caribbean). Characters associated with diversification within Psidium are discussed. Research on pre-foliation, colleters, leaf anatomy, leaf physiology, staminal development, placentation and germination associated with the anatomy of the opercular plug is desirable. Studies are biased towards sections Psidium and Obversifolia, with other sections poorly known.

Discovery of Kerivoula kachinensis and a validity of K. titania (Chiroptera: Vespertilionidae) in China

Abstract In April 2019, 15 (10♂, 5♀) Kerivoula bats were collected by harp traps from Xishuangbanna, Yunnan Province, China. External and craniodental examination, multivariate statistical analyses and molecular phylogenetic inference (CoI, Cytb and Rag2 gene markers) indicated they are Kerivoula kachinensis and Kerivoula titania, respectively. Former represents a new chiropteran record from China, while the latter is a valid occurrence of K. titania in this region because recent study indicate a misidentification of “K. titania” in Guangdong, Guangxi and Hainan, China. All specimens are presently preserved at Key Laboratory of Conservation and Application in Biodiversity of South China in Guangzhou University, Guangzhou, China. Nowadays, four woolly bats occur in China including, Kerivoula furva, K. kachinensis, Kerivoula picta and K. titania, whilst there is a risk of underestimation the actual species diversity in China region when comparing those of neighboring region such as Vietnam. Supports for field survey need to be continued in future.

Assessing the taxonomy of Heterometra-like feather stars (Echinodermata: Crinoidea: Himerometroidea) based on morphology and molecular data

The taxonomic classification of feather stars (Echinodermata: Crinoidea) has been unstable due to the extensive use of environmentally and ontogenetically variable morphological characters for diagnosing taxa. Furthermore, crinoids remain poorly studied even in some of the most biodiverse regions of the world, such as Southeast Asia. Historically, Heterometra (Comatulida: Himerometroidea: Himerometridae) has been the most abundant and speciose genus reported in Singapore, but species-level identification is challenging due to the lack of clear diagnostic features. In this study, the identities of 48 Heterometra-like crinoids collected from 21–64 m in southern Singapore were assessed based on detailed morphological examination and molecular phylogenetic inference. Specimens were initially grouped into three morphospecies, and phylogenetic analyses based on the cytochrome c oxidase subunit I gene placed these morphospecies in three distinct clades separated by large interspecific distances. Phylogenetic results coupled with additional examination of morphology confirmed the three morphotypes as Heterometra crenulata, Zygometra cf. comata, and H. schlegelii. The phylogeny further corroborates recent work showing that Heterometra is polyphyletic, with all examined species other than H. crenulata nested within the family Mariametridae, while Zygometra is nested in family Himerometridae. The separation of crenulata from other Heterometra and comparison of new material with type specimens lead us to treat this taxon as Homalometra crenulata comb. nov. and Ho. denticulata as its junior synonym. These findings highlight the need for a thorough revision of Himerometroidea.

Crithidia mellificae infection in different mammalian species in Brazil.

Crithidia mellificae, a monoxenous trypanosomatid considered restricted to insects, was recently reported to infect a bat. Herein, C. mellificae has been demonstrated to have a wider range of vertebrate hosts and distribution in Brazilian biomes than once thought. Parasites isolated from haemocultures were characterized using V7V8 SSU rDNA and glyceraldehyde 3-phosphate dehydrogenase genes. Coatis (Nasua nasua) in the Cerrado; marmosets (Callithrix sp.) and bats (Carollia perspicillata, Myotis lavali, M. izecksohni, Artibeus lituratus) in the Atlantic Forest; crab-eating foxes (Cerdocyon thous) and ocelot (Leopardus pardalis) in the Pantanal biomes were infected by trypanosomatids that displayed choanomastigote forms in haemoculture in Giemsa-stained slide smears. Molecular characterization and phylogenetic inference confirmed the infection of C. mellificae in these animals. Moreover, slight differences in C. mellificae sequences were observed. Crithidia mellificae growth curves were counted at 27°C, 36°C and 37°C, and the morphotypes were able to grow and survive for up to 16 days. Serological titers for C. mellificae were observed in nonhuman primates, demonstrating that this parasite is able to induce a humoral immune response in an infected mammal. These results showed that host specificity in trypanosomatids is complex and far from understood.

Comprehensive phylogeny of Myrmecocystus honey ants highlights cryptic diversity and infers evolution during aridification of the American Southwest

The New World ant genus Myrmecocystus Wesmael, 1838 (Formicidae: Formicinae: Lasiini) is endemic to arid and semi-arid habitats of the western United States and Mexico. Several intriguing life history traits have been described for the genus, the best-known of which are replete workers, that store liquified food in their largely expanded crops and are colloquially referred to as “honeypots”. Despite their interesting biology and ecological importance for arid ecosystems, the evolutionary history of Myrmecocystus ants is largely unknown and the current taxonomy presents an unsatisfactory systematic framework. We use ultraconserved elements to infer the evolutionary history of Myrmecocystus ants and provide a comprehensive, dated phylogenetic framework that clarifies the molecular systematics within the genus with high statistical support, reveals cryptic diversity, and reconstructs ancestral foraging activity. Using maximum likelihood, Bayesian and species tree approaches on a data set of 134 ingroup specimens (including samples from natural history collections and type material), we recover largely identical topologies that leave the position of only few clades uncertain and cover the intra- and interspecific variation of 28 of the 29 described and six undescribed species. In addition to traditional support values, such as bootstrap and posterior probability, we quantify genealogical concordance to estimate the effects of conflicting evolutionary histories on phylogenetic inference. Our analyses reveal that the current taxonomic classification of the genus is inconsistent with the molecular phylogenetic inference, and we identify cryptic diversity in seven species. Divergence dating suggests that the split between Myrmecocystus and its sister taxon Lasius occurred in the early Miocene. Crown group Myrmecocystus started diversifying about 14.08 Ma ago when the gradual aridification of the southwestern United States and northern Mexico led to formation of the American deserts and to adaptive radiations of many desert taxa.

Integrative taxonomic and geographic variation analyses in Cyrtodactylus aequalis (Squamata: Gekkonidae) from southern Myanmar (Burma): one species, two different stories

The historical accuracy of building taxonomies is improved when they are based on phylogenetic inference (i.e., the resultant classifications are less apt to misrepresent evolutionary history). In fact, taxonomies inferred from statistically significant diagnostic morphological characters in the absence of phylogenetic considerations, can contain non-monophyletic lineages. This is especially true at the species level where small amounts of gene flow may not preclude the evolution of localized adaptions in different geographic areas while underpinning the paraphyletic nature of each population with respect to the other. We illustrate this point by examining genetic and morphological variation among three putatively allopatric populations of the granite-dwelling Bent-toed Gecko Cyrtodactylus aequalis from hilly regions in southeastern Myanmar. In the absence of molecular phylogenetic inference, a compelling argument for three morphologically diagnosable species could be marshaled. However, when basing the morphological analyses of geographic variation on a molecular phylogeny, there is a more compelling argument that only one species should be recognized. We are cognizant of the fact however, that when dealing with rare species or specimens for which no molecular data are possible, judicious morphological analyses are the only option—and the desired option given the current worldwide biodiversity crisis.

Beyond endemism, expanding conservation efforts: What can new distribution records reveal?

Geographical range is one of the critical features for species conservation assessment. Nevertheless, species distribution is frequently unknown, undervalued or overlooked. During a broad taxonomic and floristic study of the southern South American prickly pear species (Opuntia spp.), new records of a species previously considered endemic to Argentina have been found in Uruguay and Brazil. Molecular phylogenetic inference was carried out to further evaluate the identity of the new records, and ecological niche models were implemented to test how the new records would fit in the previous known distribution of the species. Through molecular and morphological evidence, we confirmed the new records of Opuntia bonaerensis for Brazilian and Uruguayan floras and discussed its phylogenetic relationship and morphological similarities with closely related species. Our new records uncovered a distribution pattern congruent with the Neotropical Peripampasic Orogenic Arc, which must be further explored to better determine the biogeographic history of the species. Ecological niche models (ENM) revealed that O. bonaerensis likely had a putative ancient distribution across the grasslands and shrublands in the Pampean region largely congruent with the populations found in Brazil and Uruguay, suggesting relictual Pleistocene populations of the species and the role of glacial/interglacial cycles on the distribution of the species. In a prospective climate change scenario, ENM suggests that the species would in general be more restricted to the southernmost limits of the Pampa region and previous outlying records from Mendoza (Argentina) are a putative future refuge for O. bonaerensis. The importance of these new records for biodiversity and conservation assessment efforts that are ongoing at different scales in Brazil and neighboring areas is highlighted.

Incident infection in high-priority HIV molecular transmission clusters in the United States.

To identify correlates of incident HIV infection in rapidly growing HIV molecular clusters. Phylogenetic analysis of HIV public health surveillance data. High-priority HIV genetic transmission clusters with evidence of rapid growth in 2012 (i.e. clusters with a pairwise genetic distance ≤0.005 substitutions/site and at least three cases diagnosed in 2012) were identified using HIV-TRACE. Then, we investigated cluster growth, defined as HIV cases diagnosed in the following 5 years that were genetically linked to these clusters. For clusters that grew during the follow-up period, Bayesian molecular clock phylogenetic inference was performed to identify clusters with evidence of incident HIV infection (as opposed to diagnosis of previously infected cases) during this follow-up period. Of the 116 rapidly growing clusters identified, 73 (63%) had phylogenetic evidence for an incident HIV case during the 5-year follow-up period. Correlates of an incident HIV case arising in clusters included a greater number of diagnosed but virally unsuppressed cases in 2012, a greater number of inferred undiagnosed cases in the cluster in 2012, and a younger time of most recent common ancestor for the cluster. These findings suggest that incident infections in rapidly growing clusters originate equally from diagnosed but unsuppressed cases and undiagnosed infections. These results highlight the importance of promoting retention in care and viral suppression as well as partner notification and other case-finding activities when investigating and intervening on high-priority molecular transmission clusters.

First record of a marine microalgal species, <i>Chlorella gloriosa</i> (Trebouxiophyceae) isolated from the Dokdo Islands, Korea

Chlorella gloriosa (Chlorellaceae, Trebouxiophyceae) was isolated from seawater off the coast of the Dokdo Islands in Korea. An axenic culture was established using the streak-plate method on f/2 agar media supplemented with antibiotics, allowing identification of the isolate by morphological, molecular, and physiological analyses. The morphological characteristics observed by light and electron microscopy revealed typical morphologies of C. gloriosa species. The molecular phylogenetic inference drawn from the small-subunit 18S rRNA sequence verified that the microalgal strain belongs to C. gloriosa. Additionally, gas chromatography-mass spectrometry analysis showed that the isolate was rich in nutritionally important omega-3 and -6 polyunsaturated fatty acids and high-performance liquid chromatography analysis revealed that the high-value antioxidants lutein and violaxanthin were biosynthesized as accessory pigments by this microalga, with arabinose, galactose, and glucose as the major monosaccharides. Therefore, in this study, a Korean marine C. gloriosa species was discovered, characterized, and described, and subsequently added to the national culture collection.

New Downy Mildew Disease Caused by Hyaloperonospora brassicae on Pak choi (Brassica rapa) in Korea

Pak choi (or a Bok choy; Brassica rapa subsp. chinensis) is a popular brassicaceous vegetable worldwide. In January 2019, a downy mildew symptom on pak choi was found at a farm located in Yongin, Korea. Based on morphological characteristics and molecular phylogenetic inference, the pathogenic oomycete was identified as Hyaloperonospora brassicae. To our knowledge, this is the first report of downy mildew disease occurring on pak choi in Korea. Considering the increasing demand for this crop, this pathogen would be a potentially new threat to the cultivation of pak choi in Korea.

Phylogeny of the Eurasian genus Jurinea (Asteraceae: Cardueae): Support for a monophyletic genus concept and a first hypothesis on overall species relationships

Jurinea (Asteraceae: Cardueae) is a large Eurasian genus of about 180 species with centres of diversity in Central and Southwest Asia and the eastern Mediterranean. The genus includes many species with adaptations to xero‐ and chasmophytic habitats and comprises numerous endemics, especially in the Caucasus. Generic delimitations between Jurinea and closely related genera have been difficult to assess, as have the phylogenetic relationships with the genera Himalaiella, Jurinella and Lipschitziella, each of which has been suggested as congeneric with Jurinea. A molecular phylogenetic investigation at both the specific and the generic level to establish the generic delimitation of Jurinea and to evaluate the intergeneric relationships of the genus with other members of the Cardueae was hitherto lacking. In this study, we reconstruct the phylogenetic relationships between Jurinea and several closely related genera based on a representative taxon sampling using DNA sequence data of nuclear (ITS, ETS) and plastid DNA regions (trnK/matK, trnL‐F). We also evaluate the infrageneric classification of Jurinea. Our results indicate that Jurinea is polyphyletic in its current circumscription, as the species J. gedrosiaca and J. cartilaginea are placed within the subtribe Centaureineae of the Cardueae. The rest of Jurinea is monophyletic and split into two major clades corresponding to the western and eastern range of the distribution area of the genus. The sister clade of Jurinea is composed of Himalaiella and Lipschitziella. Jurinella, which was segregated from Jurinea based on achene morphology, is congeneric with Jurinea. Like in other speciose Eurasian genera, the currently recognised sections do not reflect natural groups, whereas most clades found through molecular phylogenetic inference correlate with geographic patterns. A clade that exclusively comprises Caucasian endemics, including the narrow endemics of J. sect. Neobellae, was found. This clade represents an interesting study group for possible radiation events of Jurinea in the Caucasus.