Hydrangeaxinfeniae (Hydrangeaceae), a new species from Sichuan, China.

Hydrangeaxinfeniae W.B.Ju & J.Ru, a new species of Hydrangeaceae from Sichuan Province, China, is described and illustrated. The new species belongs to Hydrangeasect.Dichroa (Lour.) Y.De Smet & Samain, with its distinctive characteristic being the nearly superior ovary. It shares morphological similarities with H.yaoshanensis (Y.C.Wu) Y.De Smet & C.Granados, but can be distinguished by its hirsute trichomes densely covered on the branchlets, leaves, peduncles and pedicels, broadly elliptic to rectangular-elliptic leaf blade with nearly rounded base, coarse teeth leaf margins, 3-4 pairs of lateral veins, corymbose cyme with few and loose branches, lanceolate bract, the calyx tube and lobes margin with sparsely hirsute trichomes, adaxially glabrous and abaxially sparsely hirsute petal, outer whorl filaments are linear, inner ones are awl-shaped, glabrous styles, and the nearly superior ovary. H.xinfeniaesp. nov. currently known from only three relatively small populations of the type locality, and its conservation status is assessed as Data Deficient (DD).

Mazusmotuoensis (Mazaceae), a new species from Xizang, China.

Mazusmotuoensis W.B.Ju, Bo Xu bis & X.F.Gao is a newly described species found in Xizang Autonomous Region, China. Morphologically, this species differs from all the other known Mazus species by having erect perennial herb form with a rhizome, presence of multicellular hairs, without basal leaves, opposite arrangement of stem leaves, and corolla lobes with erose-toothed margins. Molecular phylogenetic analysis using nuclear and cpDNA genes suggests that this new species occupies a basal position within Mazus. In conclusion, both morphological evidence and molecular phylogenetic analyses support that this species belongs to Mazus and represents an as-yet-unreported new species with distinct differences from other species within the genus.

Primulamedogensis, a new species of Primulaceae from Tibet of China.

We present a description of a newly discovered species, Primulamedogensis, found in southern Xizang, China. Additionally, we explore distinctive morphological characteristics that aid in its taxonomy. The new species belongs to sect. Cordifoliae and exhibits morphological similarities to P.baileyana and P.rotundifolia. However, it can be distinguished by its densely grayish-haired roots, petioles that are 3-7 times longer than the leaf blades, a short stock surrounded by straight and withered petioles, reniform leaf blades with revolute margins, scapes shorter than or equal to leave and both at flowering and in fruiting, flowers solitary on the scapes.

Primulawolongensis (Primulaceae), a new species of the primrose from Sichuan, China.

This paper describes and illustrates a new species of Primulaceae, Primulawolongensis sp. nov. from Wolong National Nature Reserve in Sichuan Province, China. It is very rare and currently only known from its type locality. The new species belongs to subsection Chartacea of the section Petiolares on account of lacking bud scales at flowering, being efarinose and having distinct petiolate leaves with more or less rounded lamina. The new species can be differentiated from other members of the subsection by leaf blade margin dentate, and leaf veins which are not raised, scape shorter than or equal to pedicels, yellow flowers and location of stamens of the corolla tube at thrum flower. Molecular phylogenetic analysis based on nuclear ribosome internal transcribed spacer (nrITS) demonstrated that P.wolongensis was sister to subgen. Auriculastrum. Primulawolongensis is currently known from a single location in Wolong Town, and its conservation status is assessed as Data Deficient (DD).

Primulalizipingensis (Primulaceae), a new species from Sichuan, China.

A new species, Primulalizipingensis W.B.Ju, L.Y.He & X.F.Gao, found in Shimian County, Sichuan, China, is described and illustrated. It is morphologically similar to P.rhodochroa and P.socialis, but can be distinguished from them in having shorter plants covering with white farinose, leaf margin sharply dentate above the middle, the leaf blade becomes papery after drying, scapes obsolete, the bract linear-lanceolate to subulate, solitary at the base of the pedicel, and the white hairs present inside the corolla tube.

Effects of topological characteristics on rhythmic states of the D-dimensional Kuramoto model in complex networks.

Synchronization is a ubiquitous phenomenon in engineering and natural ecosystems. While the dynamics of synchronization modeled by the Kuramoto model are commonly studied in two dimensions and the state of dynamic units is characterized by a scalar angle variable, we studied the Kuramoto model generalized to D dimensions in the framework of a complex network and utilized the local synchronous order parameter between the agent and its neighbors as the controllable variable to adjust the coupling strength. Here, we reported that average connectivity of networks affects the time-dependent, rhythmic, cyclic state. Importantly, we found that the level of heterogeneity of networks governs the rhythmic state in the transition process. The analytical treatment for observed scenarios in a D-dimensional Kuramoto model at D=3 was provided. These results offered a platform for a better understanding of time-dependent swarming and flocking dynamics in nature.

Chromosome-level de novo genome assembly and whole-genome resequencing of the threatened species Acanthochlamys bracteata (Velloziaceae) provide insights into alpine plant divergence in a biodiversity hotspot.

The Hengduan Mountains region is an important hotspot of alpine plant diversity and endemism. Acanthochlamys bracteata is a species of a threatened monotypic genus endemic to the Hengduan Mountains. In this study, we present a high-quality, chromosome-level reference genome for A. bracteata, constructed using long reads, short reads and Hi-C technology. We characterized its genetic diversity, population structure, demographic history and gene flow by resequencing individuals collected across its distribution. Comparative genomics analyses based on sequence information from single-copy orthologous genes revealed that A. bracteata and Dioscorea rotundata diverged ~104.5 million years ago. Whole-genome resequencing based on population genetic analysis revealed that the division of the 14 populations into 10 distinct clusters reflected geographical divergence, and three separate high levels of gene flow occurred sequentially between isolated populations of the Hengduan Mountains, a finding which is consistent with the turnover between ice ages and interglacial periods. Our findings indicate that Quaternary climatic changes played an important role in shaping the genetic structure and demographic trajectories of A. bracteata, and provide critical insights into the genetic status and evolutionary history of this poorly understood species, and possibly other alpine plants with a similar distribution. This study demonstrates the usefulness of population genomics for evaluating the effects of past climatic changes and identifying conservation units for the conservation and management of threatened species. Our high-quality genome represents a valuable resource for future studies of the underlying molecular mechanisms of adaptive evolution and provides insight for further comparative genomic analysis with other Velloziaceae species.

Hymenaspleniumtholiformis (Aspleniaceae), a new fern species from southeastern Xizang, China based on morphological and molecular evidence.

A new species of Aspleniaceae, Hymenaspleniumtholiformis sp. nov., is described from Medog County in southeastern Xizang, China. The new species is morphologically similar to H.apogamum and H.szechuanense, but the former has ascending pinnae, pinna apex obtuse to rounded, pinna-marginal teeth entire, and veins terminating just below marginal teeth. Phylogenetic analysis based on five plastid markers confirmed that this new species represents a diverging lineage in the H.excisum subclade of Hymenasplenium.

Sorbus gongshanensis (Rosaceae), a new species from the Hengduan Mountains, China.

Sorbus gongshanensis sp. nov., a new species from the Hengduan Mountains China, is described and illustrated. It is similar to S. kurzii from China (Yunnan & Xizang), Nepal, and Sikkim in the size of the leaflets, glabrous veins, persistent (sometimes) herbaceous stipules and reddish brown villous inflorescences and red fruits, but differs in its serrate leaflet margins toothed in the distal half or often almost to their base, reddish brown villous to glabrous hypanthium and reddish brown villous infructescences, among other characteristics.

Molecular phylogenetics and historical biogeography of Sorbus sensu stricto (Rosaceae).

Explaining how plants from eastern Asia migrated to other Northern Hemisphere regions is still challenging. The genus Sorbus sensu stricto (including c. 88 species) is considered as a good example to illuminate this scenario, due to the wide distribution in the temperate zone and high diversity in the Himalayas and Hengduan Mountains. Based on four nuclear markers (LEAFY-2, GBSSI-1, SBEI and WD) and one chloroplast marker (rps16-trnK), we reconstructed the phylogenetic relationship of Sorbus using 54 taxa (60% of the genus representing all subgenera, sections, or series and geographical areas in the previous classifications), and estimated divergence time and historical biogeography of the genus. Phylogenetic analyses supported that the subgenera Sorbus and Albo-carmesinae, as defined by traditional morphological characters (such as fruit color), are suitable. However, five clades defined by phylogenetic analysis of the genus are not consistent with traditionally defined sections or series. Molecular dating and biogeographic reconstruction showed that the age of the most recent common ancestor was estimated at 41mya (95% HPD: 49-35mya) in eastern Asia. Four dispersal events are assumed to explain the wide distribution of Sorbus in the temperate zone and diversification in the edges of Qinghai-Tibet Plateau (QTP). Species dispersed from eastern Asia to the Tianshan Mountains, North America and Europe during the Oligocene and Miocene period. We found that polyploidization occurred multiple times in the subgenus Albo-carmesinae, in the Tianshan Mountains, Himalayas, and H-D Mountains. Finally, we suggest that apomixis, polyploidization, and hybridization may have combined with the multistage uplifting of Himalayas and H-D Mountains (and the subsequent increases in geologic, ecological and climatic heterogeneity) to drive the striking species diversity of Sorbus in this region.

An ensemble of SVM classifiers based on gene pairs.

In this paper, a genetic algorithm (GA) based ensemble support vector machine (SVM) classifier built on gene pairs (GA-ESP) is proposed. The SVMs (base classifiers of the ensemble system) are trained on different informative gene pairs. These gene pairs are selected by the top scoring pair (TSP) criterion. Each of these pairs projects the original microarray expression onto a 2-D space. Extensive permutation of gene pairs may reveal more useful information and potentially lead to an ensemble classifier with satisfactory accuracy and interpretability. GA is further applied to select an optimized combination of base classifiers. The effectiveness of the GA-ESP classifier is evaluated on both binary-class and multi-class datasets.