of Botany,Chinese Academy Of Sciences
Not a member yet
11331 research outputs found
Sort by
Cypripedium lichiangense (Orchidaceae) mimics a humus-rich oviposition site to attract its female pollinator, Ferdinandea cuprea (Syrphidae)
No full textMost species in the genus Cypripedium (Cypripedioideae) produce trap flowers, making it a model lineage to study deceptive pollination. Floral attractants in most species studied appear to target bee species of different sizes. However, more recent publications report fly pollination in some subalpine species, suggesting novel suites of adaptive floral traits. Cypripedium lichiangense (section Trigonopedia) is an endangered subalpine species endemic to the Hengduan Mountains, China. We observed and analysed its floral traits, pollinators and breeding systems over 2 years in situ and in the lab. Cypripedium lichiangense was visited by females of Ferdinandea cuprea (Syrphidae). The pollinia were carried dorsally on the fly thoraces. The eggs of this fly were frequently found in the saccate labellum and on other floral organs, suggesting brood-site mimesis. The orchid is self-compatible, but cross-pollination produces more viable embryos. We propose a new mode of floral mimesis, humus-rich oviposition site mimicry, for C. lichiangense. Compared with the mimesis of aphid colonies attracting syrphid pollinators (subfamily Syrphinae), whose larvae are entomophagic, as reported in some Paphiopedilum species (Cypripedioideae), pollination by deceit in C. lichiangense represents a distinct and separate mode of exploitation of another saprophagic (or phytophagic) larvae syrphid lineage in the subfamily Eristalinae and appears to indicate diversity of pollination strategies in Section Trigonopedia of Cypripedium. However, this new brood-site mimesis seems to be less attractive to pollinators. As a possible adaptation to the weak attracted pollination strategy, this plant species has a long flowering period and extended lifespan of individual flowers to ensure reproductive success
The complete chloroplast genome of Pterobryopsis orientalis (Pterobryaceae, Hypnales) and its phylogenetic implications
No full textPterobryopsis orientalis (Mull. Hal.) M. Fleisch. 1917, a subtropical moss from the family Pterobryaceae, is native to the western Himalaya. In this study, the complete chloroplast genome of P. orientalis was sequenced using the Illumina NovaSeq 6000 platform, as a resource for future research on the classification and evolution of the Pterobryaceae. The genome was 124,719 bp in length, consisting of a large single-copy (LSC: 87,401 bp), a small single-copy (SSC: 18,530 bp), and two inverted repeat regions (IRs: 18,788 bp). The genome consisted of 126 unique genes, including 82 protein-coding genes, 36 tRNA genes, and eight rRNA genes. The overall GC content of the whole chloroplast genome was 52.09%. Phylogenetic analysis showed that P. orientalis is closely related to the genus Calyptothecium
Increased precipitation attenuates shrub encroachment by facilitating herbaceous growth in a Mongolian grassland
No full textWidespread shrub encroachment is profoundly impacting the structures and functions of global drylands, and precipitation change is assumed to be one of the most critical factors affecting this phenomenon. However, there is little evidence to show how precipitation changes will affect the process. In this study, we conducted a 6-year precipitation manipulation experiment (-30%, ambient, +30% and +50%) to investigate the effects of precipitation changes on the growth of shrubs and herbaceous plants in a shrub-encroached grassland in Inner Mongolia. We found that the increasing precipitation significantly increased the mean height, coverage and above-ground biomass of herbaceous species, while the growth of shrub species did not exhibit a significant response to precipitation changes. With increasing precipitation, the relative coverage of shrubs decreased, while that of herbs increased. The native dominant herbaceous plant (Leymus chinensis), with more sensitive maximum photosynthetic rate to the precipitation change, showed higher photosynthetic nitrogen use efficiency and water use efficiency than those of the encroached shrub species (Caragana microphylla) at high soil moisture contents, reflecting that the ecophysiological characteristics of L. chinensis might provide it a competitive advantage under increased precipitation. Our findings suggest that increasing precipitation may slow down shrub encroachment by facilitating herbaceous growth in Mongolian grasslands, and consequently affect the forage value and carbon budget in these ecosystems. Read the free Plain Language Summary for this article on the Journal blog
Lipid-Enhanced Photoprotection of LHCII in Membrane Nanodisc by Reducing Chlorophyll Triplet Production
No full textCarotenoid (Car) quenching chlorophyll triplet state ((3)Chl a*), an unwanted photosensitizer yielding harmful reactive oxygen species, is crucial for the survival of oxygenic photosynthetic organisms. For the major light-harvesting complex of photosystem II (LHCII) in isolated form, (3)Chl a* is deactivated via sub-nanosecond CM-to-Car triplet excitation energy transfer by lutein in the central domain of LHCII; however, the mechanistic difference from LHCII in vivo remains to be explored. To investigate the intrinsic Carphotoprotection properties of LHCII in a bio-mimicking circumstance, we reconstituted trimeric spinach LHCII into the discoidal membrane of nanosize made from L-alpha-phosphatidylcholine and examined the triplet excited dynamics. Time-resolved optical absorption combined with circular dichroism spectroscopies revealed that, with reference to LHCII in buffer, LHCII in the membrane nanodisc shows appreciable conformational variation in the neoxanthin and the Lut621 domains and in the CM a-terminal cluster owing to the lipid-protein interactions, which, in turn, alters the triplet population of Lut620 and Lut621 and their partition. Importantly, the unquenched (3)Chl a* population in the complex was reduced by 60%, indicating that LHCII in the membrane adopts a conformation that is optimized for the alleviation of photoinhibition
Bottom-up effects of plant quantity and quality on arthropod diversity across multiple trophic levels in a semi-arid grassland
No full textPlant quantity and quality can independently affect the diversity of the entire arthropod communities and multiple arthropod taxa in grassland ecosystems. However, it remains unclear how these effects on arthropod taxa at one trophic level propagate through food web to influence the diversity of higher trophic levels. We performed a monoculture experiment with 15 herbaceous species in the Inner Mongolian grassland to investigate how natural variations in plant productivity and host leaf traits affect herbivore taxon richness, which, in turn, affects predator taxon richness. For herbivores, plant productivity indirectly promoted herbivore taxon richness by increasing herbivore biomass, which was attributed to the increases in the richness of dominant sucking herbivores and endophytes with high food requirements. However, the high plant quality indicator (e.g. high leaf protein, phosphorus and water contents, and high leaf protein to carbohydrate ratio) directly increased, whereas the low plant quality indicator (e.g. high leaf lignin content) directly decreased herbivore taxon richness. Taxon richness of chewing and sucking herbivores with specific feeding modes (tearing or sucking mouthparts) showed strong positive responses to increasing plant quality. For predators, herbivore taxon richness, rather than herbivore biomass, mainly mediated the positive effects of plant productivity and the high plant quality indicator, but the negative effect of the low plant quality indicator, on predator taxon richness. At the feeding guild level, the taxon richness of parasitoids, other predators and spiders exhibited positive responses to different herbivores, which was attributed to their different diet preferences. Predator diversity could be promoted by prey partitioning among predator guilds facilitating species coexistence. At the family level, the taxon richness of most predator families was positively correlated with that of more than one herbivore family, suggesting that high predator diversity may be caused by balanced diets owing to high prey diversity. Synthesis. Natural variations in plant quantity and quality can substantially affect the diversity of herbivores and cascade up the food web to affect predators. Specificity and mechanisms of feeding have a large impact on the responses of arthropod guilds at each trophic level
A revised subfamilial classification of Polypodiaceae based on plastome, nuclear ribosomal, and morphological evidence
No full textThe polygrammoid fern family Polypodiaceae represents one of the most diversified epiphytic fern groups, with more than 1600 species distributed on all continents except Antarctica, with the highest species diversity in tropical and subtropical regions. Despite progress in recent phylogenetic studies of Polypodiaceae, the infrafamilial classification of this group of ferns is still problematic. Here, we explore the phylogenetic relationship within Polypodiaceae using plastid genome (plastome) and nuclear ribosomal cistron genome data obtained from high-throughput sequencing. Although genome skimming data strongly support the monophyly of many genera and clades of Polypodiaceae, relationships within some clades and along the backbone of the phylogeny remain incongruent between plastome and nuclear data. The explanation is possibly a factor of complex evolutionary history found in these clades, such as rapid radiation, incomplete lineage sorting, ancient hybridization, and recent introgression. Based on the concatenated dataset, our phylogenetic analyses support nine major clades in Polypodiaceae, which merit the recognition as subfamilies, Crypsinoideae, Grammitidoideae, Loxogrammoideae, Microsoroideae, Platycerioideae, Polypodioideae, Adetogrammoideae, Campyloneuroideae, and Serpocauloideae, while the latter three are separated from Polypodioideae as new subfamilies. All of these infrafamilial divisions, identified with molecular data, are further supported by non-molecular features including leaf dissection, venation, scales and paraphyses, soral features, and geographical distributions. Systematic and taxonomic discussions on the subfamilial treatment are also provided
Leaf scar and petiole anatomy reveal Pecopteris lativenosa Halle is a marattialean fern
No full textPecopteris (Brongniart) Sternberg is a morphological fossil genus with a cosmopolitan distribution during the Permo-Carboniferous, of which most species belong to the marattialean and or filicalean ferns or less frequently to pteridosperms. The taxonomic affinity is uncertain unless distinctive reproductive organs or rachis anatomy is known. Among the numerous species of Pecopteris in the Permian Wuda Tuff Flora, Inner Mongolia, China, Pecopteris lativenosa Halle has been considered as a pteridosperm based on its larger variation of frond morphology, although evidence of fertile organs or rachises are unknown. Newly discovered specimens of this species from the Wuda Tuff Flora are mostly impression fossils. However, some have partially permineralized petioles and have fronds in organic connection to Caulopteris-type stem. Fronds are tripinnate; penultimate pinnae lengths are variable as are ultimate pin-nae lengths. Pinnules are oval and thick, and their midveins are straight and are of stable thickness. Lateral veins are dense, bifurcating 1-3 times. Petiole and rachises are anatomically preserved and show sclerenchyma, fundamental tissue and vascular tissue. Vascular bundles of petioles and rachises are C -shaped with two laterally inrolled ends, which are typically stewartiopterid petiole/rachis of Marattiales. These features allow us to assign Pecopteris lativenosa to the late Paleozoic marattialean fam-ily Psaroniaceae. (c) 2022 Elsevier Masson SAS. All rights reserved
Storage, patterns and influencing factors for soil organic carbon in coastal wetlands of China
No full textSoil organic carbon (SOC) in coastal wetlands, also known as blue C, is an essential component of the global C cycles. To gain a detailed insight into blue C storage and controlling factors, we studied 142 sites across ca. 5000 km of coastal wetlands, covering temperate, subtropical, and tropical climates in China. The wetlands represented six vegetation types (Phragmites australis, mixed of P. australis and Suaeda, single Suaeda, Spartina alterniflora, mangrove [Kandelia obovata and Avicennia marina], tidal flat) and three vegetation types invaded by S. alterniflora (P. australis, K. obovata, A. marina). Our results revealed large spatial heterogeneity in SOC density of the top 1-m ranging 40-200 Mg C ha(-1), with higher values in mid-latitude regions (25-30 degrees N) compared with those in both low- (20 degrees N) and high-latitude (38-40 degrees N) regions. Vegetation type influenced SOC density, with P. australis and S. alterniflora having the largest SOC density, followed by mangrove, mixed P. australis and Suaeda, single Suaeda and tidal flat. SOC density increased by 6.25 Mg ha(-1) following S. alterniflora invasion into P. australis community but decreased by 28.56 and 8.17 Mg ha(-1) following invasion into K. obovata and A. marina communities. Based on field measurements and published literature, we calculated a total inventory of 57 x 10(6) Mg C in the top 1-m soil across China's coastal wetlands. Edaphic variables controlled SOC content, with soil chemical properties explaining the largest variance in SOC content. Climate did not control SOC content but had a strong interactive effect with edaphic variables. Plant biomass and quality traits were a minor contributor in regulating SOC content, highlighting the importance of quantity and quality of OC inputs and the balance between production and degradation within the coastal wetlands. These findings provide new insights into blue C stabilization mechanisms and sequestration capacity in coastal wetlands
(2894) Proposal to conserve Dendrobium officinale, nom. cons., against the additional name D. catenatum (Orchidaceae)
No full textMICROMORPHOLOGY, PHYTOCHEMICAL AND PHARMACOLOGICAL EVALUATION OF Isodon rugosus (Wail. ex Benth.) Codd
No full textIsodon rugosus Wall. ex Benth (IR) is one of the ethnomedicinal important plants of Gilgit-Baltistan, Northern Pakistan. The present study aims to evaluate the micro-morphological features, phytochemical screening, and pharmacological potential of IR. SEM and LM were used as an identification tool. Five different solvents were used to prepare IR extracts. Phytochemical and antioxidant activities were determined calorimetrically. To investigate antidiabetic, alpha-amylase inhibition assay was adopted. Cytotoxicity was tested using a brine shrimp assay. Anti-leishmanial via MTT assay. Disc-diffusion assay was used for protein kinase inhibitory, antibacterial, and antifungal activities. Pollen was of monad, hexacolporate, and circular shape. Lophate sculpturing with outer exine pattern elevated on the rides. Seeds were oblong-ovate, small projected with smooth-rough, variously ridges/wrinkled sculpturing. Epidermis cells were irregular in shape with a slightly straight anticlinal wall. Stomata with diacytic, and unicellular glandular trichome were observed. The extracts were rich in phytochemicals, the maximum amount of phenolic and flavonoid contents was found in methanol extract (IRM) 89.76mg GAE/gm and 85.69mg QE/gm. All the extracts show substantial antioxidant activity but highest in IRM (DPPH IC50 44.51 mu g/ml, total antioxidant capacity 93.60 mg AAE/g, and total reduction power of 93.44 mg AAE/g). Potential antibacterial and antifungal activities were reported for IRM. Significant protein kinase, alpha-amylase inhibition, and cytotoxic activity were revealed. Dose-dependent cytotoxic activity was exposed against Leishmania tropica (LC50 11.16 mu g/mL). In conclusion, I. rugosus extracts have shown potential biological applications and should be subjected to further research work to develop further biomedical applications