Towards a comprehensive phylogeny of the large temperate genus Pedicularis (Orobanchaceae), with an emphasis on species from the Himalaya-Hengduan Mountains.

BACKGROUND: Striking interspecific variations in floral traits of the large temperate genus Pedicularis have given rise to controversies concerning infra-generic classifications. To date, phylogenetic relationships within the genus have not been well resolved. The main goal of this study is to construct a backbone phylogeny of Pedicularis, with extensive sampling of species from the Himalaya-Hengduan Mountains. Phylogenetic analyses included 257 species, representing all 13 informal groups and 104 out of 130 series in the classification system of Tsoong, using sequences of the nuclear ribosomal internal transcribed spacer (nrITS) and three plastid regions (matK, rbcL and trnL-F). Bayesian inference and maximum likelihood methods were applied in separate and combined analyses of these datasets. RESULTS: Thirteen major clades are resolved with strong support, although the backbone of the tree is poorly resolved. There is little consensus between the phylogenetic tree and Tsoong's classification of Pedicularis. Only two of the 13 groups (15.4 %), and 19 of the 56 series (33.9 %) with more than one sampled species were found to be strictly monophyletic. Most opposite-/whorled-leaved species fall into a single clade, i.e. clade 1, while alternate leaves species occur in the remaining 12 clades. Excluding the widespread P. verticillata in clade 1, species from Europe and North America fall into clades 6-8. CONCLUSIONS: Our results suggest that combinations of morphological and geographic characters associated with strongly supported clades are needed to elucidate a comprehensive global phylogeny of Pedicularis. Alternate leaves are inferred to be plesiomorphic in Pedicularis, with multiple transitions to opposite/whorled phyllotaxy. Alternate-leaved species show high diversity in plant habit and floral forms. In the Himalaya-Hengduan Mountains, geographical barriers may have facilitated diversification of species with long corolla tubes, and the reproductive advantages of beakless galeas in opposite-/whorled-leaved species may boost speciation at high altitude.

MOF-Derived Bimetallic Selenide CoNiSe2 Nanododecahedrons Encapsulated in Porous Carbon Matrix as Advanced Anodes for Lithium-Ion Batteries.

Transition metal selenides have received considerable attention as promising candidates for lithium-ion battery (LIB) anode materials due to their high theoretical capacity and safety characteristics. However, their commercial viability is hampered by insufficient conductivity and volumetric fluctuations during cycling. To address these issues, we have utilized bimetallic metal-organic frameworks to fabricate CoNiSe2/C nanodecahedral composites with a high specific surface area, abundant pore structures, and a surface-coated layer of the carbon-based matrix. The optimized material, CoNiSe2/C-700, exhibited impressive Li+ storage performance with an initial discharge specific capacity of 2125.5 mA h g-1 at 0.1 A g-1 and a Coulombic efficiency of 98% over cycles. Even after 1000 cycles at 1.0 A g-1, a reversible discharge specific capacity of 549.9 mA h g-1 was achieved. The research highlights the synergistic effect of bimetallic selenides, well-defined nanodecahedral structures, stable carbon networks, and the formation of smaller particles during initial cycling, all of which contribute to improved electronic performance, reduced volume change, increased Li+ storage active sites, and shorter Li+ diffusion paths. In addition, the pseudocapacitance behavior contributes significantly to the high energy storage of Li+. These features facilitate rapid charge transfer and help maintain a stable solid-electrolyte interphase layer, which ultimately leads to an excellent electrochemical performance. This work provides a viable approach for fabricating bimetallic selenides as anode materials for high-performance LIBs through architectural engineering and compositional tailoring.

Metabarcoding revealed a high diversity of Amphidomataceae (Dinophyceae) and the seasonal distribution of their toxigenic species in the Taiwan Strait.

The dinophyte family Amphidomataceae includes the genera Azadinium and Amphidoma. Four of these species are known to produce azaspiracids, which are lipophilic phycotoxins accumulating in shellfish. The diversity and biogeography of Amphidomataceae is far from yet resolved. Here we performed a time series sampling of both water and sediments in the Taiwan Strait from Nov. 2018 to April 2021. Metabarcoding was performed to unveil the diversity of Amphidomataceae targeting internal transcribed spacer (ITS1) region and partial large subunit ribosomal DNA (LSU rDNA D1-D3), followed by quantitative PCR (qPCR) with modified primers for Az. poporum ribotypes. The diversity of Amphidomataceae was revealed from the water samples with the aid of ITS1 and LSU based molecular phylogeny. The LSU based approach detected only a few species. In contrast, ITS1 based dataset showed eight new Azadinium clades and several ZOTUs (zero-radius operational taxonomic units) grouping together with Am. languida. Moreover, eleven known Azadinium species including three ribotypes of Az. poporum and Az. dexteroporum, and two ribotypes of Az. spinosum, were detected. The latter two species have not been reported in China before. Among these toxigenic species, Az. poporum was relevantly abundant whereas others were rare. The maximum of 209 cells L -1 of Az. poporum ribotype A was estimated using qPCR nearby Quanzhou in Nov. 2018 and 172 cells L 1 of Az. poporum ribotype B was detected far off coast in Apr. 2021. Metabarcoding on sediment samples revealed Az. poporum ribotypes B and C, but strains obtained with sediment incubation experiments yielded only ribotype B. Using qPCR about 0.2 cysts g -1 of Az. poporum ribotype B were quantified in May 2019 but cysts of Az. poporum ribotype C were not detected. Our results suggest that metabarcoding targeting ITS1 region is powerful to uncover the diversity of harmful dinophytes. Our results also highlight the rich diversity of Amphidomataceae and risk potential of azaspiracids in the Taiwan Strait and surrounding waters.

Mapping harmful microalgal species by eDNA monitoring: A large-scale survey across the southwestern South China Sea.

A large-scale sampling was undertaken during a research cruise across the South China Sea in August 2016, covering an area of about 100,000 km2 to investigate the molecular diversity and distributions of micro-eukaryotic protists, with a focus on the potentially harmful microalgal (HAB) species along the east coast of Peninsular Malaysia. Environmental DNAs from 30 stations were extracted and DNA metabarcoding targeting the V4 and V9 markers in the 18S rDNA was performed. Many protistan molecular units, including previously unreported HAB taxa, were discovered for the first time in the water. Our findings also revealed interesting spatial distribution patterns, with a marked signal of compositional turnover between latitudinal regimes of water masses, where dinophytes and diatom compositions were among the most strongly enhanced at the fronts, leading to distinct niches. Our results further confirmed the widespread distribution of HAB species, such as the toxigenic Alexandrium tamiyavaichii and Pseudo-nitzschia species, and the fish-killing Margalefidinium polykrikoides and Karlodinium veneficum. The molecular information obtained from this study provides an updated HAB species inventory and a toolset that could facilitate existing HAB monitoring schemes in the region to better inform management decisions.

Co-occurrence of Alexandrium minutum (Dinophyceae) ribotypes from the Chinese and Malaysian coastal waters and their toxin production.

The bloom-forming dinophyte Alexandrium minutum comprises biogeographic inferred, global and Pacific clades with both toxic and nontoxic strains reported. A. minutum has a wide distribution in the Western Pacific, but to date only a few strains have available DNA sequences. To fully understand its genetic diversity, sampling was undertaken from the Yellow Sea, the East and South China Sea, and five strains of A. minutum and two strains of its sister species, A. tamutum, were established. Their morphology was examined by light and scanning electron microscopy. In addition, sequences were obtained from both large subunit (LSU) ribosomal DNA and/or internal transcribed spacer (ITS) region. Strains of A. minutum are morphologically indistinguishable, characterized by a smaller cell size and a narrow sixth precingular plate. In contrast, A. tamutum has a wider sixth precingular plate. High nucleotide divergences of LSU (D1-D3) rDNA and ITS were revealed amongst strains of A. minutum (10% and 25%, respectively), and A. tamutum (3% and 13%, respectively). Molecular phylogenies based on LSU rDNA and ITS revealed three ribotypes (B-D) of A. minutum, and two ribotypes of A. tamutum in the Western Pacific. Seasonal sampling in the East China Sea to detect A. minutum using the DNA metabarcoding targeting ITS1 region was also performed. Our results showed that the ribotypes B and C of A. minutum co-occurred in the water. Paralytic shellfish toxin (PSTs) of all seven strains was analysed using liquid chromatography with tandem mass spectrometry (LC-MS/MS). PSTs were detected only in A. minutum ribotypes B and C with predominance of gonyautoxins 1/4. Our results suggest high diversity and risk potential of this toxic species in this region.

Toxic dinoflagellate blooms of Gymnodinium catenatum and their cysts in Taiwan Strait and their relationship to global populations.

Gymnodinium catenatum is able to produce paralytic shellfish toxins (PSTs) and was responsible for a massive bloom in the Taiwan Strait, East China Sea, in June 2017, which resulted in serious human poisoning and economic losses. To understand the origin of the bloom and determine the potential for blooms in subsequent years, water and sediment samples collected in the Taiwan Strait from 2016 to 2019 were analyzed for cells and cysts using light microscopy (LM) and/or quantitative polymerase chain reaction (qPCR). The morphology of both cells and cysts from the field and cultures was examined with LM and scanning electron microscopy (SEM). Large subunit (LSU) and/or internal transcribed spacer (ITS)-5.8S rRNA gene sequences were obtained in 13 isolates from bloom samples and five strains from cysts. In addition, cells of strains TIO523 and GCLY02 (from the Taiwan Strait and Yellow Sea of China, respectively) were subjected to growth experiments, and cysts from the field were used for germination experiments under various temperatures. Our strains shared identical LSU and ITS-5.8S rRNA gene sequences with those from other parts of the world, and therefore belonged to a global population. A low abundance of G. catenatum cells were detected during most of the sampling period, but a small bloom was encountered in Quanzhou on June 8, 2018. Few cysts were observed in 2016 but a marked increase was observed after the bloom in 2017, with a highest density of 689 cysts cm-3. Cysts germinated at temperatures between 14 and 23 °C with a final germination rate over 93%. Strains TIO523 and GCLY02 displayed growth at temperatures between 17 and 26 °C and 14 and 26 °C, respectively, with both strains displaying the highest growth rate of ca. 0.5 divisions d-1 at 23 °C. The PSTs of the three strains and cysts from the sediments were analyzed by liquid chromatography with tandem mass spectrometry (LC-MS/MS). All strains were able to produce PSTs, which were dominated by N-sulfocarbamoyl C toxins (C1/2, 53.0-143.5 pg cell-1) and decarbamoyl gonyautoxins (dcGTX2/3, 26.7-52.1 pg cell-1), although they were not detected in cysts. However, hydroxybenzoyl (GC) toxins were detected in both cells and cysts. Our results suggested that the population in the Taiwan Strait belonged to a warm water ecotype and has a unique toxin profile. Our results also suggested that the persistence of cells in the water column may have initiated the bloom.

Phylogenetic approaches resolve taxonomical confusion in Pedicularis (Orobanchaceae): Reinstatement of Pedicularis delavayi and discovering a new species Pedicularis milliana.

Morphological identification of Pedicularis depends on floral characters. However, some important characters may be lost during the process of pressing the specimen. Pedicularis delavayi was described from northwestern Yunnan, and widely adopted as a variety of P. siphonantha. Unfortunately, the name "P. siphonantha var. delavayi' incorrectly referred to P. milliana (a new species described in this study) or P. tenuituba in some herbarium specimens and publications. Moreover, phylogenetic relationships among P. delavayi, P. siphonantha and its allies (P. milliana and P. tenuituba) were not fully resolved. In this study, we sampled 76 individuals representing 56 taxa. Of them, 10 taxa were from P. siphonantha lineage, and 11 individuals of P. delavayi represented 9 populations. These species were named as P. siphonantha group on the basis of morphological similarity. Nuclear ribosomal internal transcribed spacer (nrITS) and four chloroplast genes/regions were used for phylogenetic analyses. Phylogenetic analyses showed that the P. siphonantha group was polyphyletic: P. delavayi was sister to P. obliquigaleata in clade A; and the remaining species of P. siphonantha group were monophyletic in clade B, named as P. siphonantha lineage. In the P. siphonantha lineage, P. milliana, P. siphonantha, and P. tenuituba were well supported as monophyletic, and P. dolichosiphon was sister to P. leptosiphon. Morphologically, P. delavayi differs from species of the P. siphonantha lineage in having a long petiole (~ 50 mm) and pedicel (~ 40 mm), a ridged corolla tube, and a folded lower-lip of the corolla. Therefore, both morphological characters and phylogenetic evidence strongly supported to reinstate P. delavayi as an independent species and describe P. milliana as new species. In addition, P. neolatituba was proposed to reduce as a new synonymy of P. delavayi.