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Ctenium has about 20 species distributed in Africa, Arabia, and the Neotropics, with no species occurring on more than one continent. Its relationship with the morphologically similar Kampochloa is still unclear and has not been investigated. In this study, we performed phylogenomic analyses using 71 protein‐coding genes of 24 newly sequenced plastomes, of 13 species of Ctenium and 1 species of Kampochloa to understand their biogeography and the phylogenetic and evolutionary relationships between these two genera and within Ctenium. Our results support two major clades of Ctenium: the Neotropics and Old‐World clades. Kampochloa is shown to be a close relative of the genus Ctenium, and their morphological similarities support this. Divergence time estimation analyses show that Kampochloa and Ctenium diverged around 7.99 Ma, and might have originated in the late Miocene during the rapid expansion of C4 grasslands. With this evidence from morphology and phylogenomic data, we propose the inclusion of the previously unplaced Kampochloa into the subtribe Cteniinae. [ABSTRACT FROM AUTHOR]

Ainsliaea is an Eastern Asian genus with approximately 50 species, and is characterized by two main habit types or leaf arrangements: rosulate with leaves aggregated at the stem base or pseudo‐verticillate with leaves clustered above the stem base. Most species of Ainsliaea have been classified into two sections, A. sect. Ainsliaea and sect. Aggregatae, respectively, based on their habit type. However, recent molecular phylogenetic studies have challenged existing infrageneric classifications for Ainsliaea, and the systematic value of habit needs to be re‐evaluated because the habits of some key species were described differently, leading to taxonomic controversies on infrageneric classifications and species delimitations. To address these issues, this study reconstructed a more comprehensive phylogeny of Ainsliaea with two more samples of the highly variable A. lancifolia and a new sampling of A. nana. Habit variations in Ainsliaea were observed both in the field and in herbarium collections, and habit evolution was reconsidered based on the updated phylogeny. The phylogenetic analysis highly supports that A. uniflora and A. lancifolia form the first‐ and the second‐earliest diverging lineages in Ainsliaea, respectively; A. nana, recently rediscovered by us after more than 60 years, constitutes a distinct lineage sister to a large clade with all leaves aggregated above the stem base; and A. pertyoides forms another large clade with the rosulate‐leaf species. The latter three species have distinct habits: A. lancifolia with leaves sparsely alternate along the stem but often reduced to a basal rosette in rheophytic environments, A. nana with leaves aggregated at and also above the same stem base, and A. pertyoides with rosulate leaves when young. Thus, two new sections, A. sect. Alternae sect. nov. and A. sect. Intermediae sect. nov., are proposed to accommodate A. lancifolia and A. nana, respectively, and A. pertyoides is reasonably kept in A. sect. Ainsliaea. The results of this study provide insights into the evolution of habits in Ainsliaea and suggest that the traditional classification based solely on habit may not accurately mirror the evolutionary history of the genus. The newly proposed A. sect. Alternae and sect. Intermediae reflect a more natural classification of Ainsliaea and provide a framework for future studies on the evolution and ecology of the genus. Combining evidence from phylogeny and morphology, a conspectus of the genus and taxonomic updates for A. lancifolia, A. nana and A. pertyoides are provided. Overall, this study highlights the importance of combining molecular and morphological data to accurately classify and understand the evolutionary history of plant groups. [ABSTRACT FROM AUTHOR]

Resource partitioning is considered a key factor in alleviating competitive interactions, enabling coexistence among consumer species. However, most studies have focused on resource partitioning between species, ignoring the potentially critical role of intraspecific variation in resource use. We investigated floral resource partitioning across species, colonies, and individuals in a species‐rich bumblebee community in the diversification center of bumblebees. We used a total of 10,598 bumblebees belonging to 13 species across 5 years in the Hengduan Mountains of southwest China. First, we evaluated the influence of a comprehensive set of floral traits, including both those related to attractiveness (flower color and shape) and rewards (pollen, sugar ratio, nectar volume, sugar concentration, and amino acid content) on resource partitioning at the species level in bumblebee–plant networks. Then, we explored intraspecific resource partitioning on the colony and individual levels. Our results suggest that bumblebee species differ substantially in their use of the available floral resources, and that this mainly depends on flower attractiveness (floral color and shape). Interestingly, we also detected floral resource partitioning at the colony level within all commonest bumblebee species evaluated. In general, floral resource partitioning between bumblebee individuals decreased with species‐ and individual‐level variation in body size (intertegular span). These results suggest that bumblebee species may coexist via the flexibility in their preferences for specific floral traits, which filters up to support the co‐occurrence of high numbers of species and individuals in this global hotspot of species richness. [ABSTRACT FROM AUTHOR]

Phylogenetic placement of Hydrostachys (Hydrostachyaceae) has long been enigmatic, the highly divergent morphology of Hydrostachys having prevented its confident placement in any clade of angiosperms. Phylogenetic placements using DNA sequence data have varied, with most studies suggesting a placement within Cornales. We conducted a large‐scale phylogenetic analysis based on nuclear and chloroplast datasets to re‐examine the relationships of the genus and assess the data sources and methodological factors that may cause alternative placements. Hydrostachys was consistently recovered as a member of Cornales in all of our analyses based on 338 single‐copy nuclear genes and 78 chloroplast genes, but the divergent matK sequences of Hydrostachys available in GenBank led to different phylogenetic placements. These highly divergent DNA sequences may make phylogenetic placement problematic, and other factors may also impact the placement, including taxon sampling, long‐branch attraction, incomplete lineage sorting, and potential artifacts (from contaminants, paralogs, or assembly errors) in the datasets. [ABSTRACT FROM AUTHOR]

Studies on large‐scale geographic patterns of aquatic plant diversity can promote research on the generality of macroecological patterns in different ecosystems. Here, we compiled a checklist of 889 aquatic angiosperms in China, including 738 helophytes (emergent and marshy plants) and 151 hydrophytes (submerged, free‐floating, and floating‐leaved plants). We explore the geographic patterns and environmental correlates of aquatic plant diversity based on six metrics including species richness (SR), weighted endemism (WE), phylogenetic diversity (PD), phylogenetic endemism (PE), the standardized effect size of phylogenetic diversity (PDses), and the standardized effect size of mean phylogenetic distance (MPDses). Our results show that the diversity of aquatic plants in China is extremely uneven, with high diversity in southeastern China and low diversity in northwestern China, and the geographic patterns of taxonomic and PD are generally consistent. The pattern of helophytes differs from that of hydrophytes. Notably, the wavy‐shaped pattern of aquatic plant diversity (especially SR and PD for hydrophytes) across the latitude observed in this study is not consistent with those previously observed for aquatic plants in other continents. Climatic variables and water environmental variables are the main drivers of aquatic plant diversity in China; however, the effects of individual variables differ between helophytes and hydrophytes. Water environmental variables have a greater impact on PDses and MPDses of hydrophytes than those of helophytes. Overall, our work provides insight into understanding the large‐scale patterns of aquatic plant diversity and is a critical addition to previous studies on the macroecological pattern of terrestrial organisms. [ABSTRACT FROM AUTHOR]

Premise: A major goal of systematic biology is to uncover the evolutionary history of organisms and translate that knowledge into stable classification systems. Here, we integrate three sets of genome‐wide data to resolve phylogenetic relationships in Cornaceae (containing only Cornus s.l.), reconstruct the biogeographic history of the clade, and provide a revised classification using the PhyloCode to stabilize names for this taxonomically controversial group. Methods: We conducted phylogenetic analyses using 312 single‐copy nuclear genes and 70 plastid genes from Angiosperms353 Hyb‐Seq, plus numerous loci from RAD‐Seq. We integrated fossils using morphological data and produced a dated phylogeny for biogeographical analysis. Results: A well‐resolved, strongly supported, comprehensive phylogeny was obtained. Biogeographic analyses support an origin and rapid diversification of Cornus into four morphologically distinct major clades in the Northern Hemisphere (with an eastern Asian ancestor) during the late Cretaceous. Dispersal into Africa from eastern Asia likely occurred along the Tethys Seaway during the Paleogene, whereas dispersal into South America likely occurred during the Neogene. Diversification within the northern hemisphere likely involved repeated independent colonization of new areas during the Paleogene and Neogene along the Bering Land Bridge, the North Atlantic Land Bridge, and the Tethys Seaway. Thirteen strongly supported clades were named following rules of the PhyloCode. Conclusions: Our study provides an example of integrating genomic and morphological data to produce a robust, explicit species phylogeny that includes fossil taxa, which we translate into an updated classification scheme using the PhyloCode to stabilize names. [ABSTRACT FROM AUTHOR]

This article uses first principles to study a single molecular phase of N2O4. The structural, electronic, and vibrational properties of N2O4 under high pressure are calculated. The a‐axis and c‐axis compressibilities are basically the same. The bandgap of N2O4 decreases as the pressure increases; this is because under the action of pressure, the delocalized electrons in the system increase, so the bandgap decreases. There are two main types of N2O4 vibration: telescopic vibration and bending vibration. Herein, the calculated Raman spectrum and infrared (IR) spectrum are compared with the experimental values, and the agreement is better under normal pressure. With the increase of pressure, both the Raman and IR peaks of N2O4 appear blueshifted. This is because the applied pressure reduces the volume of the unit cell and reduces the distance between atoms, causing the movement between the atoms to intensify, so the vibration intensity increases. At the same time, under the action of pressure, N2O4 increases the IR activity in the high‐frequency region and reduces the IR activity in the low‐frequency region. [ABSTRACT FROM AUTHOR]

Members of the Poaceae family are distributed in all six vegetation types and four topographic zones in Kiambu, showing their compatibility with the habitat conditions and other coexisting species in all vegetation types. Thus, the first step towards the conservation of Poaceae and associated species in Kiambu County should be to compile a Poaceae and associated species inventory. 1 TABLENumber of Poaceae subfamilies, genera and species in Kiambu County HT

Altitudinal diversity of terrestrial plants has been widely studied, whereas little is known for the patterns of aquatic plants. Here, we used a standardised field dataset to quantify the altitudinal patterns in the diversity and structure of aquatic plant assemblages, as well as the relationships between diversity indices and environmental variables.Large‐scale field investigations were carried out in 128 sites ranging from 2,280 to 5,020 m above sea level across the southern part of Qinghai‐Tibet Plateau, China. In total, 102 species of aquatic plants were recorded, belonging to 67 genera, 31 families. Five taxonomic, phylogenetic, and functional indices were calculated for each collection site. We firstly examined altitudinal patterns of these diversity indices, then quantified the variations of indices across water areas, water flow, and soil matrix, respectively. We also explored the relationships between diversity indices and environmental variables using redundancy and variance partitioning analysis, to detect the ecological variables that drove the diversity.The results showed that taxonomic, phylogenetic, and functional diversity of aquatic plants decreased with increasing altitude. Net relatedness index of aquatic plants showed a hump pattern along the altitude gradient, with a peak around 3,800 m above sea level. There was no obvious trend in the net functional relatedness index of aquatic plants with altitude. Annual mean temperature was the most important variable associated with the taxonomic, phylogenetic, and functional diversity. Water area and water flow were significantly associated with functional structure, but not phylogenetic structure. Soil matrix also correlated with aquatic plant diversity.A large‐scale altitudinal gradient can influence aquatic plant diversity. Environmental filtering and niche convergence might have played dominant roles in the increasing and decreasing stages of phylogenetic structure of aquatic plant assemblages, respectively, along the altitudinal gradient. Phylogenetic and functional structure of aquatic plant assemblages showed different patterns along the altitudinal gradient, and the environmental variables better explained the change of functional structure than did the phylogenetic variables.This is the first comprehensive study on the species, phylogeny, and function of aquatic plant assemblages along a large‐scale altitudinal gradient. We found an altitudinal decline in the diversity of aquatic plants and different patterns in the phylogenetic and functional structures of aquatic plant assemblages. These findings indicate that functional traits have high phenotypic plasticity and are more affected by environments than phylogenetic relationships which are mainly shaped by evolutionary processes. [ABSTRACT FROM AUTHOR]

Ponerorchis wolongensis, a new orchid species from the Hengduan Mountains, western Sichuan, China, is described and illustrated here based on morphological and phylogenetic evidence. Morphologically, the new species is similar to P. capitata, but they can easily be differentiated by the number of leaves and flowers, the shape of leaves, and the mid‐lobe of the labellum. Phylogenetically, based on seven DNA sequences, the new species is more close to P. sichuanica, but these two species are very different in both growth habit and morphological characteristics. [ABSTRACT FROM AUTHOR]

Streptocarpus ionanthus (Gesneriaceae) is endemic to Tanzania and Kenya, distributed in Tanga, Morogoro, and Kilifi regions. The species houses nine subspecies characterized by complex morphotypes and poorly understood evolutionary relationships, and thus is an ideal model for investigating evolutionary dynamics over time. Using multiple methods, we sought to test our hypothesis that the infraspecific taxa in Str. ionanthus are slightly variable and evolving populations. We first examined the genetic diversity, population differentiation, and phylogeographic structure among the populations of Str. ionanthus using both chloroplast and nuclear markers. We then estimated the divergence time of Str. ionanthus lineages and modeled past and future distribution. Despite Str. ionanthus exhibiting bottleneck events across its range, the populations maintain relatively high genetic diversity attributed to historical population admixture or local adaptation arising from habitat heterogeneity. The phylogeographic and genetic structure revealed a high connection among the Usambara mountains populations, while molecular dating suggested most diversification of haplotypes began ~1.32–0.18 million years ago and intensified toward the present, a conclusion of recent diversification. Phylogenetic relationship of Str. ionanthus cpDNA haplotypes revealed five main lineages with unique haplotypes that could be suggestive of past isolated refugia during the Pleistocene climate shifts. According to niche modeling, the stability of suitable areas during the Last Glacial Maximum (LGM) offered protective micro‐habitats that have preserved the genetic diversity of Str. ionanthus to date. In conclusion, our findings suggest a complex Str. ionanthus with slightly variable lineages or populations attributed to multiple refugia and on the verge of divergence. [ABSTRACT FROM AUTHOR]

Woody and herbaceous plants are differentially influenced by the environment, with non‐random association with the evolutionary history of these taxa and their traits. In general, woody plants may have climate‐dominated niches, whereas herbaceous plants may have edaphic and microhabitat‐dominated niches. Here, we explored and mapped how the patterns of species richness, phylogenetic diversity, and structures of total, woody, and herbaceous plants vary across the geographical regions and with respect to 12 environmental variables across Ethiopia and Eritrea, in the horn of Africa. Our result showed that both richness and phylogenetic diversity had almost the same tendency in total woody and herbaceous plants, in which they showed positive relationships with annual precipitation, precipitation annual range of climate, all the three variables of topography, and total nitrogen and total extractable phosphorus of soil, and negative relations with mean annual temperature. Compared with the total and herbaceous plants, the environmental variables explained greater variance both in the standardized effect size phylogenetic diversity and net relatedness index for woody plants. Our results highlight that, on the large spatial scales, the environmental filtering process has played a greater role in structuring species into local communities for woody plants than for herbaceous plants. [ABSTRACT FROM AUTHOR]

Lysionotus coccinus G.W. Hu & Q.F. Wang, a distinct new species from Yingjiang County, southwestern Yunnan Province, China, is described and illustrated. It belongs to L. sect. Lysionotus, but has scarlet flowers while all other known species in this section have white, yellow, purple or pink flowers. Color photographs and a chart are provided for comparing the new species with related species. [ABSTRACT FROM AUTHOR]

Adequate characterization of soil organic carbon (SOC) fractions is essential to elucidate carbon dynamics in permafrost‐affected ecosystems. SOC and its fractions were investigated across alpine ecosystems, including alpine swamp meadows (ASM), alpine meadows (AM) and alpine steppes (AS), in permafrost regions on the Qinghai–Tibet Plateau (QTP), southwest China. The density separation method was used to separate the SOC into light‐ and heavy‐fraction organic carbon (LFOC and HFOC, respectively). Permafrost soils in the ASM had higher SOC, LFOC, and HFOC contents than in the AM. LFOC and HFOC contents were significantly correlated, but both were more closely related to SOC than to each other. On the ecological gradient from ASM to AS, the thickness of surficial organic horizons decreased while the thickness of mineral materials increased. SOC in the organic horizon and permafrost had high mineralization probability. At soil depths of 0–200 cm in ASM, AM, and AS, the SOC stocks were 123, 71, and 25 kg m−2; LFOC stocks were 70, 49, and 12 kg m−2; and HFOC stocks were 58, 37, and 15 kg m−2, respectively. These results show that SOC fractions vary with vegetation type and active layer thickness, thus making SOC sensitive to changes in environmental conditions. Therefore, the decomposition of SOC in permafrost‐affected soils of the QTP could be accelerated over a degrading permafrost and under a warming climate. [ABSTRACT FROM AUTHOR]

Traditional attempts to delineate floristic regions are typically based on the qualitative analysis of species distribution, often ignoring the phylogenetic relationships among their taxa. Ethiopia and Eritrea are in the Horn of Africa, known as one of the world's biodiversity hotspots. We quantitatively classified the flora of Ethiopia and Eritrea into meaningful geographical units by analyzing the taxonomic and phylogenetic β‐diversity at genera, total species, and endemic species levels at a scale of 0.5° × 0.5° grid cells. Hierarchical clustering was used to quantitatively delimitate the flora and analysis of similarities was used to test the significant difference between the derived groups in taxonomic composition and phylogenetic relatedness. In total, two floristic subprovinces, five floristic districts, and 13 floristic subdistricts, as well as three centers of species endemism associated with three floristic subdistricts were identified. Our results also showed that the species diversity, endemism, and turnover of the highlands in Ethiopia and Eritrea were much higher than the lowlands, indicating that the floristic differences are closely related to the topography of the East African Rift. In this study, we provided a scientific framework for the composition and relationships of the floristic units in the Horn of Africa, and similarly provided a scientific basis for better conservation of the diversity in this region. [ABSTRACT FROM AUTHOR]

1. In many flowering plants, bumble bees may forage as both pollinators and nectar robbers. This mixed foraging behaviour may be influenced by community context and consequently, potentially affect pollination of the focal plant. 2. Salvia przewalskii is both pollinated and robbed exclusively by bumble bees. In the present study area, it was legitimately visited by two species of bumble bees with different tongue length, Bombus friseanus and Bombus religiosus, but it was only robbed by Bombus friseanus, the shorter‐tongued bumble bee. The intensity of nectar robbing and pollinator visitation rate to the plant were investigated across 26 communities in the Hengduan Mountains in East Himalaya during a 2‐year project. For each of these communities, the floral diversity, and the population size and floral resource of S. przewalskii were quantified. The abundances of the two bumble bee species were also recorded. 3. Both nectar robbing and pollinator visitation rate were influenced by floral diversity. However, pollinator visitation rate was not affected by nectar robbing. The results revealed that relative abundance of the two bumble bee species significantly influenced the incidence of nectar robbing but not the pollinator visitation rate. Increased abundance of B. religiosus, the legitimate visitors, exacerbated nectar robbing, possibly by causing B. friseanus to shift to robbing; however, pollinator visitation remained at a relatively high level. 4. The results may help to explain the persistence of both nectar robbing and pollination, and suggest that, in comparison to pollination, nectar robbing is a more unstable event in a community. [ABSTRACT FROM AUTHOR]

• Premise of the study: Simple sequence repeat (SSR) markers were derived from transcriptomic data for Ottelia acuminata (Hydrocharitaceae), a species comprising five endemic and highly endangered varieties in China. • Methods and Results: Sixteen novel SSR markers were developed for O. acuminata var. jingxiensis. One to eight alleles per locus were found, with a mean of 2.896. The observed and expected heterozygosity ranged from 0.000 to 1.000 and 0.000 to 0.793, respectively. Interestingly, in cross-varietal amplification, 13 out of the 16 loci were successfully amplified in O. acuminata var. acuminata, and 12 amplified in each of the other three varieties of O. acuminata. • Conclusions: These newly developed SSR markers will facilitate further study of genetic variation and provide important genetic data needed for appropriate conservation of natural populations of all varieties of O. acuminata. [ABSTRACT FROM AUTHOR]

Plant mating systems rapidly respond to pollen limitation in changing environments. However, whether and how floral traits are involved in a mating system shift requires further investigation. A widely distributed and bumblebee-pollinated lousewort, Pedicularis siphonantha D. Don was studied. We investigated pollination systems, reproductive success, and floral traits in four large populations growing from 3200 m to 4300 m. Pollinator activity in low altitude populations was lower and these populations had a decreased fruit set and seed number per capsule compared to populations at high altitudes. Supplemental hand pollination with outcross pollen significantly increased seed production per capsule for plants from high altitudes but not for those from lower altitudes. We also found that bumblebees visited more flowers within an inflorescence in a single foraging bout in high altitudes compared with low altitudes, which caused a high possibility of geitonogamous mating. These differences may be pollination-dependent rather than inheritance-based because hand pollination on bagged flowers did not cause a difference in seed production across populations. Compared to plants from low altitudes, high-altitude plants had increased flower longevity, larger floral displays, higher pollen production per flower, and shorter corolla tubes, which were found to be well in accordance with changes in both pollination environment and mating system. Plasticity in floral traits might help plants to adjust their resource allocation strategies in response to their habitat, which might be linked with pollination environment. The variability among these populations might be beneficial for this widely distributed species to cope with environmental changes. [ABSTRACT FROM AUTHOR]

Background Complement factor H (CFH) related proteins (CFHRs) play important roles in complement activation pathways, whereas previous studies have only shown that CFH can affect the development of uveitis. In the present study, we investigated the potential associations between one of single-nucleotide polymorphisms in the CFHR2 gene with acute anterior uveitis (AAU). Methods A total of 571 subjects, 283 patients diagnosed with AAU and 288 healthy adult controls, were recruited for this case-control study. CFHR2-rs2986127 was detected using Sequenom MassARRAY technology (Sequenom, San Diego, CA, USA). Results The stratified analyses for AAU patients with ankylosing spondylitis (AS) revealed a reduced frequency of the A allele in CFHR2-rs2986127 compared to controls ( p = 0.033, odds ratio = 0.563, 95% confidence interval = 330-0.960). Further stratified analyses revealed a similar significantly reduced frequency in male AAU patients with AS compared to male controls ( p = 0.036, odds ratio = 0.514, 95% confidence interval = 0.274-0.965) and in AAU patients without posterior segment involvement compared to controls ( p = 0.048). Conclusions The present study reveals an association between CFHR2-rs2986127 and AAU diagnosis, especially with respect to gender, AS status and other clinical signs, such as posterior segment involvement. Our results may further enrich the growing understanding of uveitis genetics, and raise the clinical diagnostic accuracy of this disease. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Although aquatic plants are discussed as a unified biological group, they are phylogenetically well dispersed across the angiosperms. In this study, we annotated the aquatic taxa on the tree of vascular plants, and extracted the topology of these aquatic lineages to construct the tree of aquatic angiosperms. We also reconstructed the ancestral areas of aquatic families. We found that aquatic angiosperms could be divided into two different categories: the four aquatic orders and the aquatic taxa in terrestrial orders. Aquatic lineages evolved early in the radiation of angiosperms, both in the orders Nymphaeales and Ceratophyllales and among basal monocots (Acorales and Alismatales). These aquatic orders do not have any extant terrestrial relatives. They originated from aquatic habitats during the Early Cretaceous. Asia would have been one of the centers for early diversification of aquatic angiosperms. The aquatic families within terrestrial orders may originate from other areas besides Asia, such as America or Australia. The lineages leading to extant angiosperms diversified early in underexploited freshwater habitats. The four extant aquatic orders were relicts of an early radiation of angiosperm in aquatic environments. Their extinct ancestors might be aquatic early angiosperms. [ABSTRACT FROM AUTHOR]

The article presents an introduction to this issue of the journal that consists of papers related to the giant phylogeny of the Chinese vascular plants.

Lobelioideae comprise about 1200 species in 30 genera worldwide and include famous cases of parallel evolution in the "giant rosette" lobelias occurring in East Africa, Hawaii, and Bhutan. To date, no phylogeny has included the Himalayan giant lobelia, and its age and phylogenetic distance from the Hawaiian and African giant species (the latter in the same section as the Bhutan species) are therefore unknown. Asian Lobelioideae in general have received little attention, partly because of the difficult access to material. Here we use nuclear and plastid markers of Lobelioideae (with worldwide sampling) to test the monophyly of the section that includes most Asian lobelias, and we then use a reduced concatenated matrix to resolve the position of Lobelia nubigena from Bhutan and of the likewise cold‐adapted lowland species L. sessilifolia. Most sequences come from herbarium material. Lobelia nubigena diverged from its Asian lowland relatives 13.8 (12.6–15) million years ago (about the time of the Bhutan Himalaya orogeny), and in an unexpected twist, L. sessilifolia is the sister species to a huge clade (ca. 265 species) that comprises African, South American, Asian, and the entire Hawaiian Lobelioideae radiation. The African and Hawaiian high‐elevation lobelias in our sample are younger than L. nubigena, although the time when gigantism evolved in this species cannot be precisely inferred. Our results support the previously hypothesized Asian origin of (1) the Hawaiian Lobelioideae, (2) Southeast Asian islands lobelias, and (3) the African Lobelia‐Rynchopetalum group, which also reached South America. [ABSTRACT FROM AUTHOR]

Sensitive stigma has been recognized to facilitate outcrossing. We hypothesized that species with different levels of sensitivity might have corresponding differences in components of their breeding system. In this study, three Mazus species with bilobed stigmas were used to test the hypothesis. We explored stigma behaviors of the species in reaction time, recovery time, permanent closing time, and the minimum pollen load causing permanent closure. We investigated floral traits, pollinator type and behavior, pollination intensity, and natural schedule of pollen deposition on stigma. Moreover, we evaluated the mating system of the species by checking seed set after controlled pollination treatments, namely, natural flowers with open pollination, enclosed flowers without pollination, and enclosed flowers with self and outcross hand pollination. Results indicated that stigma of M. pumilus (N. L. Burman) Steenis was not sensitive, whereas stigmas of M. miquelii Makino and M. stachydifolius (Turcz.) Maxim. closed and reopened quickly in response to pollination. Accordingly, hand pollination treatments revealed that seed set of self-spontaneous pollination in M. pumilus was similar to the other treatments. For M. miquelii, outcross pollen resulted in significantly higher seed set than self-pollen. Mazus stachydifolius was self-incompatible. Additionally, the corresponding characteristics in other components of the breeding system for each species were found. Our study indicated that the sensitivity of bilobed stigma might be linked with floral traits and the mating system in a given species. Sensitive stigma should be regarded as an evolutionary mechanism for enhancement of outcrossing. [ABSTRACT FROM AUTHOR]

Many phylogeographic studies of terrestrial plant species on the Qinghai-Tibet Plateau (QTP) have been carried out to elucidate the range shifts in response to climatic oscillations in the Quaternary. However, patterns of range shifts for aquatic plants following the climate change on the QTP are poorly understood. Here, we studied the historical range shifts of the aquatic herb Ranunculus bungei Steud. on the QTP using four chloroplast (cpDNA) non-coding spacers. We revealed low within-population genetic diversity ( HS = 0.052) and high interpopulation genetic differentiation ( GST = 0.914; NST = 0.954). But the high population differentiation was not coupled with a distinct phylogeographic structure ( NST > GST, P > 0.05). Phylogenetic analyses revealed two main cpDNA haplotype lineages and the split between these two lineages can be dated back to the late Tertiary (3.84-11.90 Ma). Two independent range expansions within the two intraspecific lineages at approximately 0.15-0.46 and 0.17-0.50 Ma were revealed. Our results suggested that R. bungei survived the Last Glacial Maximum and/or previous glacial periods on the QTP. Colonization or recolonization during the repeated range expansions may have replaced the early haplotypes and the pre-existing genetic structure and could explain the non-significant phylogeographical structure. [ABSTRACT FROM AUTHOR]

Ailanthus altissima (Mill.) Swingle, a temperate tree species, has a wide distribution in China. To infer its refugia and patterns of migration during past climatic changes in China, genetic variations among different populations were studied. Gene sequences of three chloroplast DNA spacer regions, psbA-trnH, trnL-trnF, and trnD-trnT, were obtained from 440 individuals of 44 populations. The distribution of haplotype and the relationships among them were investigated by haplotype network. In addition, the genetic diversity of the sampled regions was inferred, and the biogeographic history was also reconstructed. Twelve haplotypes were identified, among which, five were unique. The phylogenetic analysis and geographical distribution of haplotypes indicate that multiple glacial refugia existed in mainland China during the Quaternary oscillations. Due to the combined effects of contiguous range expansion and allopatric fragmentation, significant genetic structure was not found in this study. Based on biogeographic and demographic analysis, three main dispersal routes were identified for the major haplotypes, whereas others were more likely localized demographic expansion. [ABSTRACT FROM AUTHOR]

Nymphoides peltata is a distylous aquatic plant. In order to explore the relative importance of clonal growth and sexual reproduction within populations and also to reveal the origin of the commonly occurring one style morph populations in China, we studied the clonal diversity and population genetic structure of this species. By using seven single sequence repeat primer pairs, a total of 192 multilocus genotypes (MLGs) were identified among the 472 samples from the 21 populations analyzed; each population had two or more MLGs. The number of MLGs was lower for the one style morph populations than distylous populations. Analysis of molecular variance showed that a smaller proportion of genetic variation resided among populations (36.8%). A neighbor-joining tree indicated that there was no significant geographical structure of the genetic variation among populations of N. peltata. The Bottleneck tests indicated that there had been significant bottlenecks in most of the studied populations. The successful sexual recruitment from seeds may have contributed to the high clonal diversity in distylous populations of N. peltata in China. Demographic stochasticity or bottleneck should account for the one style morph population with several MLGs. And also the bottleneck effects or demographic changes caused by human activities occurring randomly in populations should account for the finding of no significant geographical structure of the genetic variation among the investigated populations of N. peltata. [ABSTRACT FROM AUTHOR]

Resource allocation, as well as the tradeoffs among different reproductive components, plays an important role in the adaptability of plants to different environments. The hybrid may exhibit a higher adaptability in life history in heterogeneous environments because of the genetic variation derived from its parents. In this study, we exploited three levels of water depths and two types of sediments to investigate the resource allocation pattern of the first generation of the natural hybrid Potamogeton × intortifolius compared to its parents P. wrightii and P. perfoliatus. We also measured the ramet survivorship and the seed set of the hybrid P. × intortifolius. Our results showed that P. × intortifolius had higher ramet survival than its parents at 1.5-m water depth on clay sediment. The possible tradeoffs showed that in P. × intortifolius the tradeoff pattern between sexual and clonal reproduction was more pronounced in limiting environments. The individuals allocated more resources to sexual reproduction when the environment was limiting, which might confer a higher ability to utilize resources, to produce offspring and to found new populations. Although the seed set of P. × intortifolius was lower than its parents, it had a higher ability to increase its seed set when the environment was limiting (sandy sediment) than its parents, which might benefit its future survival. These results indicated that the F1 hybrid P. × intortifolius was more able to adapt to limiting environments than one or both of its two parental taxa. [ABSTRACT FROM AUTHOR]

The genus Cucurbita (Cucurbitaceae) includes five species that were domesticated independently in the Americas, giving rise to an immense diversity of squashes, pumpkins, and gourds. To gain an improved understanding of the evolution of Cucurbita and its domesticated taxa, we used four chloroplast loci to estimate the phylogeny of 23 taxa that represent the broad-level diversity within Cucurbita. Our results provide a strongly supported framework hypothesis for the phylogeny of the genus, robustly confirming the basal position of the C. digitata group of xerophytic perennials and the monophyly of a large group of mesophytic annuals that represent most of the known diversity in the genus, both wild and domesticated. The chloroplast evidence provides strong support for a novel grouping of the mesophytic annual C. ficifolia (known only from cultivation) with the xerophytic perennials C. foetidissima and C. pedatifolia. This study also provides the first DNA-based evidence in support of the isozyme-based hypothesis that C. pepo subsp. ovifera var. ovifera (represented by most ornamental gourds and several squashes) was domesticated from the wild taxon C. pepo subsp. ovifera var. ozarkana. This lends support to the hypothesis that var. ovifera was domesticated in the eastern United States and that this region served as one of about 10 independent centers of origin of human agriculture. Although the level of bootstrap support for this and certain other peripheral relationships in Cucurbita is low, definitive resolution of these issues is within reach, as next-generation sequencing should soon deliver entire organelle genome sequences from a comprehensive sampling of the genus. [ABSTRACT FROM AUTHOR]