Coccoidea (Hemiptera, Sternorrhyncha) are widely distributed and agriculturally significant insects known for their distinctive morphology and biological traits. The Coccoidea are often called scales or mealybugs because many species have a shell-like covering resembling a scale or are covered with mealy wax. Knowledge of scale insects beyond the female adult stage is limited, partly because other life stages are less conspicuous, shorter-lived, and less impactful on host plants. This complicates accurate classification, further compounded by limited molecular phylogenetic studies. This study presents the first phylogenetic analyses combining genome and transcriptome sequence data. We sequenced five whole genomes and one transcriptome from Pseudococcidae and integrated these new genome-scale data with existing genome and transcriptome sequences to perform phylogenomic analysis of scale insects. The analysis yielded robustly supported relationships within Coccoidea, resolving several high-level relationships. The current genome-scale data support the monophyly of Monophlebidae, Pseudococcidae, Kerriidae, and Diaspididae, while not supporting the monophyly of Coccidae and Eriococcidae. Bayesian inferences using site-heterogeneous models corroborated Pseudococcidae as the sister group of all other neococcoid families. Within Pseudococcidae, two subfamilies, Phenacoccinae and Pseudococcinae, were supported. At the tribe level, Phenacoccini was found to be monophyletic, whereas Planococcini, Trabutinini, and Pseudococcini were not.

Five new spider fossils of the family Macrothelidae (Araneae: Mygalomorphae) are described from mid-Cretaceous Kachin amber, Myanmar. A new genus Acanthomacrothele gen. nov. is established for three new species: Acanthomacrothele pauciverrucae sp. nov., Acanthomacrothele geminata sp. nov., and Acanthomacrothele longicaudata sp. nov. Both male and female specimens of A. pauciverrucae sp. nov. are described, representing a rare case of a fossil spider with both sexes known. We also describe an unidentified juvenile of Macrothelidae to document different developmental stages of Cretaceous species. To test the phylogenetic position of the new fossils, we undertook phylogenetic analyses using both topology-unconstrained and topology-constrained methods. Our analyses supported the placement of Acanthomacrothele gen. nov. in Macrothelidae, although its phylogenetic relationship to other genera of Macrothelidae differed among different analytical methods. The fossils documented here have elongated, widely spaced posterior lateral spinnerets, compact rectangular group of eyes on a tubercle, and more spines on male tibia of anterior legs than female, similar to extant macrothelids, suggesting that they probably have similar retreat construction behavior, habitat preference, and mating position to their living relatives.

Rich materials can provide more opportunities for exploring the mechanisms of speciation driven by sexual selection. Being the fastest-evolving arthropods to date, the sword-tailed crickets of Nudilla Gorochov, 1988 (= Laupala Otte, 1994) have rapidly diverged primarily due to the variability of their calling songs (sexual signals). In addition, they also exhibit morphological conservatism, with little variation between species. Similar circumstances can be seen in tree crickets (Oecanthinae), which have conservative morphology and a diverse range of song variations. Thus, we believe that tree crickets could serve as a model for research on sexual selection since they share a similar evolutionary history and mode of differentiation with Nudilla. However, due to the improper methods in analyzing the calling songs and nearly identical morphological features between taxa, there are many problems with the taxonomy of Oecanthinae in China. To solve these problems, we conducted an integrative taxonomic study of Chinese Oecanthinae based on comparative morphology, species delimitation, acoustical analysis, and phylogenetic analysis. This study recognized 12 Oecanthinae species in China, including four new species, and confirmed one new synonym and two misidentifications. Meanwhile, we confirmed the morphological stability of Oecanthinae, and revealed that variation in color, size, and morphology may be intraspecific polymorphism, which sometimes does not reflect the species relationships. The result indicates that the acoustic parameter freq.median can be used for efficient and accurate species delimitation in Oecanthinae. We speculate that incomplete species divergence leads to complexity in species relationships at the genetic level of Oecanthinae. The conservation of morphological characters, the interspecificity of songs and the complexity of species relationships suggest that sexual selection have played a role in the evolution of Oecanthinae. Our study resolves some systematic and taxonomic problems of Oecanthinae, clarifies the species relationships of Oecanthinae in China, and provides clues for expanding the cricket groups to be used in speciation studies.

Panax (Araliaceae) is a small genus containing several well known medicinally important species. It has a disjunct distribution between Eastern Asia and Eastern North America, with most species from eastern Asia, especially the Himalayan-Hengduan Mountains (HHM). This study used the genomic target enrichment method to obtain 358 nuclear ortholog loci and complete plastome sequences from 59 accessions representing all 18 species of the genus. Divergence time estimation and biogeographic analyses suggest that Panax was probably widely distributed from North America to Asia during the middle Eocene. During the late Eocene to Oligocene Panax may have experienced extensive extinctions during global climate cooling. It survived and diverged early in the mountains of Southwest China and tropical Indochina, where some taxa migrated northwestward to the HHM, eastward to central and eastern China, and then onward toward Japan and North America. Gene flow is identified as the main contributor to phylogenetic discordance (33.46%) within Panax. We hypothesize that the common ancestors of the medicinally important P. ginseng + P. japonicus + P. quinquefolius clade had experienced allopolyploidization, which increased adaptability to cooler and drier environments. During the middle to late Miocene, several dispersals occurred from the region of the HHM to contiguous areas, suggesting that HHM acted as a refugium and also served as a secondary diversification center for Panax. Our findings highlight that the interplay of orographic uplift and climatic changes in the HHM greatly contributed to the species diversity of Panax.

Koelerioid grasses (subtribe Aveninae, tribe Poeae; Pooideae) resolve into two major clades, here called Koelerioid Clade A and Clade B. Phylogenetic relationships among koelerioid grasses are investigated using plastid DNA sequences of rpl32‐trnL, rps16‐trnK, rps16 intron, and ITS regions, focusing on Trisetum, Acrospelion, and some annual species (Rostraria p.p. and Trisetaria p.p.) closely related to Trisetum flavescens in Koelerioid Clade A. Phylogenetic analyses of several selected data sets performed for 80 taxa and using Maximum Likelihood and Bayesian methods, revealed mostly congruent topologies in the nuclear and plastid trees, but also reticulation affecting several lineages. Trisetum is restricted to one species, Trisetum flavescens, which is sister to the clade formed by Trisetum gracile and Trisetaria aurea. The latter two species are classified here in the genus Graciliotrisetum gen. nov. The sister clade includes three species of Rostraria and Trisetaria lapalmae, all of which are classified here in a resurrected genus, Aegialina, which includes four species. Acrospelion is enlarged to include 13 species after the addition of other species formerly classified in Trisetum sect. Trisetum and T. sect. Acrospelion. We also transfer Trisetum ambiguum, T. longiglume, and Koeleria mendocinensis to Graphephorum; and Helictotrichon delavayi to Tzveleviochloa, expanding these genera to eight and six species, respectively. We evaluate cases of reticulate evolution between Koelerioid Clades A and B and within Koelerioid Clade A, which probably gave rise to Graphephorum, Rostraria cristata and Rostraria obtusiflora, respectively. Finally, we comment on polyploidy and biogeographic patterns in koelerioid grasses. We propose the following 26 new combinations: Acrospelion alpestre, A. altaicum, A. argenteum, A. bertolonii, A., buschianum, A. buschianum ssp. transcaucasicum, A. fuscum, A. laconicum, A. macrotrichum, A. rigidum, A. rigidum ssp. teberdense, A. tamonanteae, A. velutinum, Aegialina lapalmae, A. pubescens, A. pumila, A. pumila ssp. fuscescens, A. salzmannii, A. salzmannii ssp. cossoniana, Graciliotrisetum aureum, G. gracile, Graphephorum ambiguum, G. longiglume, G. mendocinense, G. orthochaetum, and Tzveleviochloa delavayi. Lectotypes are designated for the names Aegialitis tenuis, Aira melicoides, Avena aspera var. parviflora, Avena delavayi, Koeleria grisebachii var. mendocinensis, K. pubescens ssp. cossoniana, K. pumila, K. salzmannii, Phalaris pubescens, Trisetum aureum, T. cernuum, T. fuscescens, T. longiglume and, T. wolfii; and we designate one neotype for Alopecurus litoreus.

Several species in the genus Oxalis occupy Peruvian fog oases (Lomas) with a significant habitat-adapted and endemic diversity. Acknowledging this aspect, the genus Oxalis is a conceivable group for evolutionary and biogeographic hypothesis testing; however, molecular resources for the genus still need improvement. We conducted a genome skimming approach to assemble new plastomes from 18 accessions (six species) of Oxalis collected in Lomas locations in Peru. These complete plastomes of Oxalis species (several reported for the first time) present a highly conserved composition. Our phylogenetic results were congruent with previous section-based backbone phylogenies of Oxalis; however, a closer look at the phylogeny of sect. Carnosae revealed nonmonophyletic arrangements involving Oxalis megalorrhiza and Oxalis bulbocastanum individuals. We also propose a set of three hypervariable plastid regions as potential molecular markers. Likewise, an array of primers for nuclear simple sequence repeat markers based on the most widely distributed species, O. megalorrhiza, were listed and evaluated for their transferability to the other species under examination. These new genomic resources represent a significant development for future population, phylogenetic, and biogeographic studies in Oxalis.

Gene duplications have contributed to the innovation of morphological traits during plant evolution. An outstanding example is the role of CYCLOIDEA2 (CYC2) gene duplications in the formation of the complex structure of Asteraceae capitula. Previous studies have shown that Chrysanthemum lavandulifolium (Fischer ex Trautv.) Makino and a few other species of the Asteraceae harbor two copies of CYC2e. Here, we identified a lineage-specific CYC2e duplication event at the root of the phylogeny of the tribe Anthemideae by analyzing the evolutionary history of CYC2 genes across the Asteraceae. Although the gene expression patterns of CYC2e1 and CYC2e2 were similar in most of floral organs, CYC2e1 promoted ligule elongation by promoting cell expansion, whereas CYC2e2 showed a weak inhibiting effect on the ray-floret development, and overexpression of CYC2e2 resulted in the maldevelopment of stamens in disc florets. These results indicated differentiated functions of CYC2e1 and CYC2e2 in the capitulum development of the Anthemideae. Given the previous data that identified CYC2g and CYC2d as main regulators in ligule morphogenesis, we comparatively analyzed 10 Asteraceae genomic data, and identified tandem arrays of CYC2g, CYC2d, and CYC2e. We further investigated the regulatory relationships between CYC2g/CYC2d and CYC2e genes, and found that CYC2g can activate the expression of CYC2e1. The findings of this study elucidate the synergistic roles of CYC2 genes in regulating the formation of the Asteraceae capitula and enhance understanding of the mechanism of duplicated gene retention during plant evolution.

The orchid Dactylorhiza cantabrica H.A. Pedersen is a narrow endemic occurring in the western Cantabrian Mountains in northwest Spain. Previous allozyme and morphological studies suggest that it might have resulted from the hybridization of two widespread congeners: the triploid Dactylorhiza insularis and the diploid Dactylorhiza sambucina. However, this hypothesis has not been tested using multiple genetic markers necessary to analyze phylogenies in complex genera such as Dactylorhiza. In this study, the Hyb-Seq technique is applied together with the universal Angiosperms353 probe kit to sequence multiple plastid and low-copy nuclear genes. The phylogenetic relationships between the three species, estimated based on 269 and 266 nuclear genes under concatenation and coalescent-based approaches, respectively, revealed highly supported clades containing each putative parent, D. insularis and D. sambucina. The position of D. cantabrica was not well resolved, suggesting the existence of mixed inheritance, where different genes come from each parent. Phylogenetic networks, used for visualizing the conflict between nuclear gene trees, placed D. cantabrica between the two parents and revealed high levels of reticulation. In addition, nuclear genetic variation within and among species was explored with allele frequency-based tools further supporting the intermediate position of D. cantabrica and the hypothesis of a recent hybrid origin. Finally, 75 plastid genes revealed that D. insularis might have been the maternal donor. Altogether, our results point to the allopolyploid origin of D. cantabrica from D. insularis and D. sambucina, as well as to the clear genetic differentiation of the two parental species.

Aquilaria (Thymelaeaceae), a tropical and subtropical plant, is one of the main genera that can produce agarwood. Aquilaria sinensis and Aquilaria yunnanensis are native Chinese tree species, and A. sinensis is China's main agarwood source. Agarwood is a nontimber forest product with high economic and medicinal value. First-grade agarwood is sold as much as $100 000 per kilogram. There has been little research on the saprobic fungi associated with Aquilaria, with only 11 records having been reported. In the present study, 10 terrestrial saprobic fungi associated with A. sinensis and A. yunnanensis were collected in China. Based on morphological and phylogenetic studies, these 10 collections are introduced herein as one new genus (Aquilariomyces), nine new species – Aquilariomyces aquilariae, Corynespora aquilariae, Melomastia maomingensis, Nigrograna aquilariae, Parathyridariella aquilariae, Peroneutypa maomingensis, Phaeoseptum aquilariae, Pseudothyridariella aquilariae, and Triangularia aquilariae, and one known species (Camarographium clematidis). Descriptions, illustrations of morphological characteristics, photo plates, phylogenetic trees, and the results of a pairwise homoplasy index test (PHI) test results are provided.

Fossil wood is one of the crucial proxies for understanding terrestrial vegetation composition and development in the Earth's history. The gymnosperm wood taxon Xenoxylon Gothan is a significant member of the Mesozoic flora. To date, more than 20 species of Xenoxylon have been described. However, its botanical affinities have remained enigmatic ever since it was described, over a century ago. Here we perform a phylogenetic analysis of Xenoxylon to understand the systematic relationship with extant conifers. Data come from four nucleotide regions (trnL-F, trnK-matK, rbcL, psbA-trnH), xylological characters, and biomolecular composition of five extant conifer families; for Xenoxylon, no nucleotide data are available. Using maximum parsimony in Tree Analysis using New Technology, Xenoxylon appeared basal to Araucariaceae in the data set combining genes and xylological characters, whereas Xenoxylon is placed next to Podocarpaceae in the data set combining genes and biomolecular characters. To find a reliable systematic placement of Xenoxylon, a combined data set of genes, xylological and biomolecular characters is analyzed. Our results and interpretations indicate that Xenoxylon is closely related to Podocarpaceae. This first phylogenetic analysis of Xenoxylon fills the knowledge gap of the systematic relationship of this taxon and contributes to a better understanding of the evolution of extant Podocarpaceae.

Rhododendron is a significant plant genus, with over 600 identified species in China. The subgenus Hymenanthes holds the largest number of Rhododendron germplasms and showcases strong environmental adaptability. However, there remains a lack of understanding regarding Rhododendron's evolution and environmental adaptations. Rhododendron bailiense Y.P.Ma, C.Q.Zhang & D.F.Chamb., an exceedingly rare species, thrives in the alkaline karst landforms of Guizhou, southwest China, different from the typical growing environment of other Rhododendron species. In this study, we present a chromosome-level genome assembly of R. bailiense, revealing a genome size of 923.3 Mb, a contig N50 of 24.5 Mb, and a total of 47 567 predicted genes. An evolutionary analysis indicated that R. bailiense diverged from its ancestors prior to the other subgenus Hymenanthes rhododendrons, with the expanded and contracted genes being notably enriched in “stress response” and “growth,” respectively. Rhododendron bailiense is predominantly found on limestone soil in the mountains of Guizhou, with only two wild populations known. The genome of R. bailiense contained a high copy number of ankyrin repeat (ANK) and Ca²⁺-ATPase (CAP) genes, primarily involved in Ca²⁺ transport, shedding light on how R. bailiense copes with karst high-calcium stress. In contrast, the structures of the ANKs displayed unique characteristics, while the CAPs showed conservatism. The R. bailiense genome provides new insights into the adaptation and evolutionary history of Rhododendron plants in karst environments, potentially offering valuable information for adaptive breeding and ecological enhancement in such challenging settings.

The genus Didymocarpus Wall. is a core group of the subfamily Didymocarpoideae in Gesneriaceae with a complex taxonomic history. It has long been controversial to delimit Didymocarpus and its allies. We conducted phylogenetic reconstructions with high-density sampling of Didymocarpus and related genera by using four nuclear ribosomal DNAs (external transcribed spacer [ETS], internal transcribed spacer [ITS], 18S, 26S) and five chloroplast DNAs (atpB-rbcL, rpl16, rps16, trnH-psbA, and trnL-F). The results indicated that neither Didymocarpus nor Allocheilos are monophyletic. Based on molecular phylogenetic and morphological analyses, we delimitated the range of the Didymocarpus sensu stricto (s. str.) with two-section division, and established a new genus Palmatiboea for species originally placed in Didymocarpus. This genus is remarkably distinguished from Didymocarpus s. str. not only in molecular phylogeny and morphology but also in its specific geographic distribution, in that it is found only in Southeast China. In addition, we proposed a new monotypic genus Hequnia for Allocheilos guangxiensis that is completely isolated in phylogeny, consistent with a range of remarkably distinctive morphological characteristics. Our results clarify the systematics of Didymocarpus and the delimitation between it and related genera with establishment of two new genera.

During the Cretaceous period, the lacewing superfamily Mantispoidea, with an assemblage of species possessing raptorial forelegs, have undergone a rapid species radiation, characterized by abundant species richness and high morphological plasticity. Nevertheless, the morphology and early evolution of the specialized predatory organ around the time of its origin in raptorial Mantispoidea have been poorly documented due to the rarity of fossil evidence, especially for the pre-Cretaceous fossils. Herein, a new genus and new species, that is Archarhachiberotha longitarsa Wang, Ren et Wang gen. et sp. nov., was described from the Middle Jurassic Jiulongshan Formation of northeastern China. This new genus was characterized by the remarkable raptorial forelegs, that is, typically elongated coxa, relatively less-swollen femur and rudimentary small femoral spines, and well-developed tarsi. Considering the peculiar morphological combination and antiquity of the new genus, it was assigned to be a stem-group lineage of Mantispoidea. Also, the detailed analyses of morphology and biological functions of raptorial forelegs were made to conclude that the new genus evolved into an unknown but primitive raptorial type that was distinctly different from the extant morphological features and raptorial mechanisms. In addition, the evolutionary tendency of raptorial Mantispoidea herein summarized highlights morphological diversity and disparity between fossil and extant representatives, and provides a rare case to explore the entire evolutionary history of a specialized structure in one lineage.

For clades originating in warm climates, the tropical niche conservatism hypothesis predicts that current biological assemblages in colder or drier climates are expected to have lower phylogenetic diversity, and species in colder or drier climates are expected to be more closely related to each other (i.e., higher phylogenetic clustering). Liverworts are one of the oldest clades of extant land plants. They originated about 500 Ma during a warm (“greenhouse”) period and experienced multiple major cycles of warm and cold periods. Here, I test the tropical niche conservatism hypothesis using liverwort assemblages distributed along an elevational gradient crossing about 5000 m of elevation in the central Himalaya. I found that, in general, phylogenetic diversity and dispersion decrease with increasing elevation and thus with decreasing temperature, which is consistent with the tropical niche conservatism hypothesis. Phylogenetic diversity decreases with elevation monotonically, but phylogenetic dispersion decreases with elevation in a triphasic (zig-zag) pattern, which is generally consistent with the triphasic pattern found in angiosperms and polypod ferns along the same elevational gradient. Temperature-related variables explained approximately the same amount of the variation in phylogenetic diversity and dispersion as did precipitation-related variables, although mean annual temperature explained 9%−15% more variation than did annual precipitation. Climate extreme variables explained approximately the same amount of variation in phylogenetic diversity and dispersion as did climate seasonality variables.

Speciation events often occur with adaptive radiation. The factors that promote these adaptive radiating species diversity patterns have intrigued biologists for more than a century. In the present study, we used the adaptive radiated genus Ligustrum to evaluate the relative contributions of the environment, species interactions, phylogenetic diversity, and diversification rates in generating extant species diversity patterns. Using complete chloroplast genome data, we reconstructed the highly supported and dated backbone phylogenetic relationships of Ligustrum. Biogeographic results indicated that Ligustrum originated in Southwest China during the Oligocene and spread to suitable areas that were warm and humid via 18 dispersal events. For the overlapping ranges of species pairs, a smaller phylogenetic distance was detected in high species overlap than in low species overlap, which is consistent with no significant difference in niche among the different species. We found that the phylogenetic diversity and interspecies competition induced by insignificant niche divergence shaped the global pattern of Ligustrum diversity.

We describe a new species of Ampelopsideae (Vitaceae), Nekemias mucronata sp. nov., from the Rupelian of Cervera (Spain) and revise another fossil species, Ampelopsis hibschii, originally described from Germany. Comparison with extant Ampelopsideae suggests that the North American species Nekemias arborea is most similar to Nekemias mucronata while the East Mediterranean Ampelopsis orientalis is the closest living relative of A. hibschii. Our review of fossil data indicates that, during the Eocene, four species of Ampelopsideae occurred in Eurasia, that is, N. mucronata in the Czech Republic, A. hibschii in Kazakhstan, and two fossil species in the Far East (Ampelopsis cercidifolia and Ampelopsis protoheterophylla). In the Oligocene, a new species, Ampelopsis schischkinii, appeared in Kazakhstan; meanwhile, N. mucronata spread eastwards and southwards, and A. hibschii mainly grew in Central Europe. In the late Oligocene, N. mucronata became a relict in the Iberian Peninsula and Nekemias might have persisted in Western Eurasia until the latest Miocene (“Ampelopsis” abkhasica). The last occurrence of A. hibschii was in the Middle Miocene in Bulgaria, probably a refuge of humid temperate taxa, along with Ampelopsis aff. cordata. Carpological remains suggest that this lineage persisted in Europe at least until the Pleistocene. Our data confirm previous notions of the North Atlantic and Bering land bridges being important dispersal routes for Ampelopsideae. However, such dispersion probably occurred during the Paleogene rather than the Neogene, as previously suggested. A single species of Ampelopsideae, A. orientalis, has survived in Western Eurasia, which appears to have been linked to a biome shift.

The daisy tribe Anthemideae Cass. is one of the largest and most diverse tribes within Asteraceae. We analyzed a data set including 61 out of 111 Anthemideae genera, and all but four of the 19 currently recognized subtribes (Inulantherinae, Lapidophorinae, Lonadinae, and Vogtiinae) using a targeted high-throughput sequencing approach, the first focused on the tribe. We followed different phylogenomic approaches, using nuclear and plastid data, as well as additional analytical methods to estimate divergence times and diversification rates, to unravel the evolutionary history and classification of this tribe. Our results reinforce the phylogenetic backbone of the Anthemideae advanced in previous studies and further reveal the possible occurrence of ancient hybridization events, plastid capture, and/or incomplete lineage sorting (ILS), suggesting that complex evolutionary processes have played an important role in the evolution of this tribe. The results also support the merging of subtribe Physmasperminae into Athanasiinae and subtribe Matricariinae into Anthemidinae and clarify previously unresolved relationships. Furthermore, the study provides additional insights into the biogeographic patterns within the tribe by identifying three main groups: the Southern African Grade, the Asian Clade, and the circum-Mediterranean Clade. These groups partially coincide with previously identified ones. Overall, this research provides a more detailed understanding of the Anthemideae tribe and improves its classification. The study also emphasizes the importance of phylogenomic approaches for deciphering the evolutionary dynamics of large and diverse plant lineages.

Tetradium, a genus within Rutaceae, comprises nine species found in Eastern and Southeastern Asia, distinguished by their opposite pinnate leaves and apocarpous or subapocarpous gynoecium with follicular fruits. While Hartley's 1981 monograph provided foundational insights, a comprehensive phylogenetic analysis of the genus is lacking. Using next-generation sequencing (NGS), this study aims to (i) establish an NGS molecular data set for Tetradium, (ii) elucidate interspecific relationships via the hybrid capture method and (iii) investigate the taxonomic status of Euodia meliifolia var. celebica. Our data set comprised 28 samples across nine species, sequenced using Illumina Miseq and Hiseq 4000 platforms, with downstream analyses conducted using the HybPhyloMaker pipeline and ASTRAL. Our findings revealed five main groups supported by both molecular and morphological data, highlighting changes in ovule number and seed functionality. Notably, the hybrid capture method proved invaluable for studying old herbarium specimens. Finally, taxonomic revisions were proposed, including the reclassification of E. meliifolia var. celebica as Tetradium celebicum, the fossil Euodia costata as Tetradium costatum, and the fossil Euodia lignata as Tetradium lignatum. An updated description for T. celebicum, supplemented by a specific identification key, is provided.

Assessing sampling biases caused by nonrandom specimen collecting is crucial in systematics, biogeography, and conservation. Nevertheless, research on the collecting biases of vascular plants in China remains limited. Here, we investigated the collecting status of gymnosperms in China using 48 673 herbarium specimens representing 180 Chinese gymnosperm species. The spatial and temporal patterns, collector and determiner biases, and phylogenetic and taxon biases were studied to comprehend the collecting bias of gymnosperms in China during 1900–2021. Meanwhile, we assessed the inventory completeness of gymnosperms to identify collecting hotspots and coldspots. The results showed that gymnosperms predominantly inhabit mountainous areas in China. The historical collecting of gymnosperms in China can be divided into two distinct stages with four peaks of collecting activities. The distribution of collected or identified specimens per individual displays significant skewness, and the collecting of gymnosperms has the issues of overcollecting or undersampling. Inventory completeness remains deficient, and collecting intensity is weak in both northern China and the range of 22°–25° N in the southern region (i.e., central Yunnan, southern Guangxi, and eastern Guangdong). Additionally, observation of the spatial distribution reveals both hotspots and coldspots scattered across mountain regions, lacking clustering. This study revealed a highly polarized collecting pattern for gymnosperms in China. Consequently, we recommend optimizing collecting measures, targeted specimen collecting, and continuous dynamic monitoring of gymnosperms in future collecting efforts. These recommendations hold relevance not only for gymnosperms in China but also for other land plants worldwide.

The wild rats in the genus Rattus represent a group of murids characterized by rapid lineage diversification but limited morphological variation. Within this genus, there are several commensal species with high invasive capacity, such as Rattus norvegicus and R. rattus, which pose a global threat. Investigating the mechanisms behind their adaptive evolution is of utmost importance. In this study, we conducted morphological study and whole-genome sequencing on Rattus species distributed in China and adjacent regions to gain insights into morphological differentiation, as well as genomic divergence and gene flow using assembled mitochondrion genome and high-quality single nucleotide polymorphisms. Despite their morphological similarity and large overlap in morphospace, our analyses revealed significant genetic differentiation at the genomic level among Rattus species in China and adjacent regions. Specifically, intraspecific differentiation was observed in R. nitidus, R. norvegicus, and R. tanezumi, which may be related to habitat heterogeneity and geographic isolation. We hypothesize that as invasive rats expand their habitat, the diversification of ecological environments might lead to more environmentally adapted evolution and accelerated genetic differentiation. Furthermore, Dsuite and TreeMix analyses detected substantial introgression among different Rattus species, particularly evident between R. norvegicus and R. tanezumi. Strong gene flow signals suggest frequent hybridization events among these species, which may facilitate the acquisition of new environmental adaptability during their expansion into new territories. This study provides a preliminary analysis that serves as a foundation for a more comprehensive investigation into the rapid lineage diversification and adaptive introgression among Rattus species.

A full understanding of local adaptation at the genomic level will help to elucidate its role in the differentiation between closely related species. This study focused on rice seed bugs sister species (Leptocorisa chinensis and Leptocorisa oratoria), which are native to East Asia and are notorious pests targeting growing rice spikelets. East Asia is a region where diverse geology and fluctuating climate are known to have profound impacts on organisms. In this study, single nucleotide polymorphisms (SNPs) from double-digest restriction site-associated DNA sequencing and geographic distribution information were used to investigate phylogeography and assess the environmental contribution to genetic variation. We found clear genetic differentiation between sister species, but a lack of genetic structure within species because of their long-distance dispersal ability. The demographic model involved a scenario in which divergence in isolation (~0.6 Ma) was followed by secondary contact (~7 kya). The initial divergence may have been caused by the intensification of the East Asian monsoon during the Pleistocene climate oscillation. The historical demography indicated that the effective population size (N_e) showed an evident increase from 9 to 7 kya, which may be related to rice domestication and extensive human cultivation during the Holocene. We also detected a significant correlation between genetic and environmental distance, and the niche difference occupied between them. Temperature-related variables were ranked as the main factors for the difference, and 410 selective SNPs involved in adaptation were identified. The Nanling Mountains in southern China serve as a geographical boundary between them and act as an ecological barrier belt that promotes local environmental adaptation. Our study demonstrates that historical climate change and local adaptation by climate-imposed selection shape the phylogeographical patterns of sister species.

Based on several earwigfly specimens with well-preserved mouthparts of Meropeidae from mid-Cretaceous Burmese amber, a detailed, initial analysis was conducted of the structure of Mesozoic meropeids. Compared to the singularly flattened mandible of modern meropeids, the new specimens reveal that Mesozoic representatives had two distinct types of mandibles: blade-shaped and scoop-shaped. Current fossil evidence indicates that during the Mesozoic Era, Meropeidae displayed sexual dimorphism that was reflected in the structure of their mandibles. This structural difference may indicate that about 99 million years ago, meropeids had a more complex diet than extant confamilial taxa. Phylogenetic results suggest that Torvimerope gen. nov., along with Burmomerope, two extinct genera, form a clade and that are the sister taxon to crown-group Meropeidae. The new material offers new possibilities for inferring the feeding habits and mating behavior of early Meropeidae.

Ecological interactions and evolutionary processes in areas of endemism remain little studied despite the fact that identifying the patterns of functional signatures in areas of endemism could reveal important information regarding community assembly and functioning. Here, we investigated whether areas of endemism of the orchids of Megamexico are hotspots of biotic interactions by comparing the orchid–pollinator interactions with those of adjacent areas. Patterns of functional signatures and phylogenetic signal were estimated, using pollination syndromes as a proxy for functional attributes. Phylogenetic signal was estimated by coding pollinator groups for every orchid recorded. Metrics of the interaction networks and the phylogenetic signal were compared with those obtained from adjacent areas. Our results indicate that areas of endemism show higher significant differences in the phylogenetic signal compared with adjacent areas. This can be explained by the many distantly related orchid lineages sharing attributes related to pollination. Network size and robustness differed statistically between the areas of endemism and the adjacent areas. The same configuration of modules in interaction networks was found in the areas of endemism; however, remarkably, the composition of species in large genera differed in these areas. Areas of endemism harbor more orchid lineages that closely interact with many groups of insects. The southerly areas of endemism in Chiapas and Central America are prominent, with the most significant phylogenetic signal and networks metrics. Results indicate that areas of endemism for the orchids of Megamexico represent hotspots of biotic interactions. Strategies for conservation must take this biotic interaction into account.

Oleaceae, a eudicot family with great species diversity, has attracted much attention from botanists because it contains many plants with important economic, medicinal, and ornamental values. However, the history of polyploidization and ancestral genome reshuffling of Oleaceae remains unclear. Here, we clarified an Oleaceae-common hexaploidization (OCH) event occurring at ~53–61 million years ago (Ma) common in all Oleaceae plants and an Oleaceae-recent tetraploidization (ORT) event occurring at ~18–21 Ma shared by the lineages of Syringa, Olea, Osmanthus, and Fraxinus. We found that high-frequency polyploidization events drove the frequency of gene loss in Oleaceae genomes and extended the size of regions containing adjacent gene loss, thereby promoting the degree of genome fragmentation. We revealed that biased fractionation between the OCH- and ORT-produced subgenomes is likely attributed to the origin of allopolyploidization in the OCH and ORT events. Significantly, through paleochromosome rearrangement comparisons, we proposed a "two-step" genome duplication model for OCH and determined the duplicated orders of OCH tripled genome. We reconstructed 11 protochromosomes of the most recent ancestral Oleaceae karyotype (AOK) and elucidated the trajectories of immense paleochromosome reorganization of Oleaceae species from ancestral eudicot karyotype. Notably, we tracked the diversification history of secondary metabolite synthesis genes in the Oleaceae and explored the effects of paleogenome evolution on specialized metabolite synthesis. Our findings provide new insights into the polyploidization and paleogenomic evolution of Oleaceae and have important scientific significance for understanding the genetic basis of species and secondary metabolic diversity in Oleaceae.

Eucalypt fossils were widely reported from the Cenozoic deposits across the Southern Hemisphere (Australia, New Zealand, and Argentina). However, no attached reproductive and vegetative fossil remains of this myrtaceous clade have been discovered till now. We report and describe for the first time a fossil eucalypt twig with attached foliage, flower buds, and mature flowers from the early Eocene (~55-52 Ma) sediments (Palana Formation) of Rajasthan, western India. As both vegetative and reproductive organs are in organic connection, they clearly represent the same species. In addition, here we also introduce fossil materials of isolated leaves, flower buds, inflorescence, and flowers recovered from the same stratigraphic level. Our Eocene fossils and extant members of the eucalypt clade are related morphologically by means of robust, thick petiolate lanceolate-shaped leaves with intramarginal secondary veins; operculate flower buds consisting of imbricate petals with discernable margins; solitary inflorescence with three flowers per umbellaster, epigynous and bisexual flowers. Based upon combined characteristics of leaf, flower, and bud morphology, these fossils conform to the Eucalypt clade and are recognized as a new fossil genus and species: Hindeucalyptus eocenicus Patel, R.F. Almeida, Ali et Khan gen. nov. et sp. nov. We also compare it with extant and extinct eucalypts using morphological phylogeny and character mapping analyses. In addition, we briefly discuss its phytogeographic and paleoclimatic implications regarding the distribution and habitat of fossil and modern eucalypts.

Dipelta Maxim. (Caprifoliaceae) is a Tertiary relic genus endemic to China, which includes three extant species, Dipelta floribunda, Dipelta yunnanensis, and Dipelta elegans. Recent progress in the systematics and phylogeographics of Dipelta has greatly broadened our knowledge about its origin and evolution, however, conflicted phylogenetic relationships and divergence times have been reported and warrant further investigation. Here, we utilized chloroplast genomes and population-level genomic data restriction site-associated DNA-single nucleotide polymorphisms (RAD-SNPs) to evaluate the interspecific relationships, population genetic structure and demographic histories of this genus. Our results confirmed the sister relationship between D. elegans and the D. yunnanensis-D. floribunda group, but with cyto-nuclear phylogenetic discordance observed in the latter. Coalescent simulations suggested that this discordance might be attributed to asymmetric “chloroplast capture” through introgressive hybridization between the two parapatric species. Our fossil-calibrated plastid chronogram of Dipsacales and the coalescent modeling based on nuclear RAD-SNPs simultaneously suggested that the three species of Dipelta diversified at the late Miocene, which may be related to the uplift of the eastern part of Qinghai-Tibet Plateau (QTP) and adjacent southwest China, and increasing Asian interior aridification since the late Miocene; while in the mid-Pleistocene, the climatic transition and continuous uplift of the QTP, triggered allopatric speciation via geographical isolation for D. floribunda and D. yunnanensis regardless of bidirectional gene flow. Based on both plastid and nuclear genome-scale data, our findings provide the most comprehensive and reliable phylogeny and evolutionary histories for Dipelta and enable further understanding of the origin and evolution of floristic endemisms of China.

Taxonomy of Populus is a challenging task, especially in regions with complex topography, such as the Qinghai-Tibet Plateau because of the effect of hybridization, incomplete lineage sorting, phenotypic plasticity, and convergence. In the Flora of China, Populus pseudoglanca and Populus wuana are classified into sect. Leucoides and sect. Tacamahaca, respectively, but their taxonomy remains unclear. By conducting a systematic investigation for all taxa of Populus on the plateau, we found 31 taxa from the two sections. Through identification based on morphology and habitats, we confirmed that the “P. pseudoglanca” recorded in the Flora of Sichuan is not true P. pseudoglanca, while P. pseudoglanca and P. wuana recorded in the Flora of China may refer to the same species. By performing whole-genome re-sequencing of 150 individuals from the 31 taxa, we derived 2.28 million single nucleotide polymorphisms (SNPs). Further genetic and phylogenetic analyses demonstrated that the genetic structure of P. wuana is extremely consistent with P. pseudoglanca, and they all originate through the natural hybridization between Populus ciliata in sect. Leucoides and Populus curviserrata in sect. Tacamahaca. Our results suggested that P. wuana should be merged with P. pseudoglanca taxonomically. This study not only clarifies the taxonomic confusions related to P. pseudoglanca and P. wuana but also provides a new framework based on the integration of morphology, distribution, habitat, and genome to solve complex taxonomic problems.

Tongoloa is a herbaceous genus of East Asia Clade (Apiaceae) distributed in the alpine regions. The use of DNA fragments has not provided a well-resolved evolutionary history. For this research, we primarily collected samples from the type localities of Tongoloa and closely related taxa in the Hengduan Mountains. The chloroplast (cp) genomes and nuclear ribosomal (nr) DNA repeats of 27 taxa were assembled using genome skimming sequencing reads. We analyzed the characteristics of the Tongoloa cp genome, and found a remarkable expansion of the Inverted Repeats. Three genes (ndhC, ndhJ, and petG) related to photosynthesis appear to have undergone significant selective pressure. Through high-resolution phylogenetic analysis, the cpDNA provided compelling evidence supporting the inclusion of Sinolimprichtia as an early taxon within Tongoloa. However, the nrDNA suggested that Tongoloa and Sinolimprichtia belong to distinct branches. Morphological analysis showed that Tongoloa has broadly oval fruits with a cordate base, whereas the fruits of Sinolimprichtia are long-obovate with an obtuse base. The specific fruit morphology of Sinolimprichtia was found to be nested within Tongoloa in the cpDNA phylogenetic tree. Ancient introgression and chloroplast capture provide the most plausible explanation for the significant conflict between the nrDNA and cpDNA phylogenies. Our study highlights the potential impact of the complex evolutionary history of Tongoloa on the challenges encountered in previous taxonomic treatments.