Functions of arbuscular mycorrhizal fungi in regulating endangered species Heptacodium miconioides growth and drought stress tolerance.

KEY MESSAGE: The important values of AMF in regulating endangered species Heptacodium miconioides growth and drought stress tolerance. The wild endangered tree Heptacodium miconioides is distributed sporadically in mountainous areas and often subjected to various abiotic stresses, such as drought. The mutualistic association between plants and arbuscular mycorrhizal fungi (AMF) is known to have a significant impact on plant growth and their ability to withstand drought conditions. However, the role of AMF in H. miconioides seedlings in regulating drought tolerance remains unknown. This study investigated the ability of AMF symbionts to mitigate drought and their underlying mechanism on H. miconioides leaves. The results showed that drought stress dramatically decreased the leaf biomass and damaged the chloroplast structure in seedlings. Conversely, inoculation with AMF noticeably alleviated the deleterious effects of drought stress by restoring leaf morphology and improving the photosynthetic capacity. Moreover, plants inoculated with AMF enhanced the proportion of palisade tissue to spongy tissue in the leaves and the size of starch grains and number of plastoglobules in the chloroplast ultrastructure. A transcriptomic analysis showed that 2157 genes (691 upregulated and 1466 downregulated) were differentially expressed between drought stress with AMF inoculation and drought treatment. Further examination demonstrated that the genes exhibiting differential expression were predominantly associated with the advancement of photosynthesis, sucrose and starch metabolism, nitrogen metabolism, chloroplast development, and phenylpropanoid biosynthetic pathways, and the key potential genes were screened. These findings conclusively provided the physiological and molecular mechanisms that underlie improved drought resistance in H. miconioides in the presence of AMF, which could contribute to improving the survival and species conservation of H. miconioides.

Reproductive biology of an endangered lithophytic shrub and implications for its conservation.

BACKGROUND: Plants in cliff habitats may evolve specific reproductive strategies to cope with harsh environments, and unraveling these reproductive characteristics can improve our understanding of survival strategies and lithophyte evolution. This understanding is especially important for efforts to protect rare and endemic plants. Here, we investigated the reproductive biology of Lonicera oblata, an endangered lithophytic shrub that is scattered in highly fragmented and isolated cliff habitats of the Taihang and Yan mountains in North China. RESULTS: Flowers of L. oblata are herkogamous and protandrous, characteristics that can prevent autogamy at the single-flower level, and insects are necessary for pollination. The outcrossing index, pollen/ovule ratio, and the results of hand pollination were measured and all revealed a mixed mating system for L. oblata, that combines cross-fertilization and partial self-fertilization. The floral traits of L. oblata of zygomorphic and brightly yellowish corolla, heavy fragrance, and rich nectar, suggest an entomophilous pollination system. Sweat bees were observed as the most effective pollinators but their visiting frequencies were not high. Pollen limitation may limit the reproductive success of L. oblata. CONCLUSIONS: We determined the reproductive characteristics of L. oblata, a critically endangered species endemic to cliffs in North China, providing insight into its endangerment and suggesting conservation strategies. L. oblata has highly pollinator-dependent self-fertilization as part of a mixed mating system. Floral features such as low-flowering synchrony, asynchronous anthers dehiscence, and high duration of stigma receptivity, improve pollination efficiency in the case of low pollinator service. Our work provides reference information to understand the survival strategies and conservation of L. oblata and other lithophytes.

First report of leaf anthracnose on the Whorled Sunflower, Helianthus verticillatus, caused by Colletotrichum fioriniae in the United States.

Whorled sunflower, Helianthus verticillatus Small, is an endangered (U.S. Fish and Wildlife Service 2014) perennial sunflower species indigenous to the southern United States (Matthews et al. 2002; Ellis et al. 2008). Helianthus verticillatus has a showy yellow floral display in the Fall that attracts a diversity of insect visitors (Strange et al. 2020). Its hardiness in the landscape and late-season blooming makes it a potential ornamental (Trigiano et al. 2021). In June 2021, anthracnose-like lesions were observed on mature leaves collected from potted H. verticillatus plants grown in the nursery compound at the University of Tennessee, Knoxville, TN, USA. Irregularly shaped leaf spots with 1‒2 mm tan centers were observed on mature leaves, which later expanded to 3‒5 mm, and became dark brown- to- black surrounded by chlorotic halos (Fig.1). Lesions from three infected leaves were excised from a single potted plant, trimmed to 1.5-cm squares with green borders, and surface-sterilized (Trigiano et al. 2018). Tissues were placed onto potato dextrose agar (PDA), amended with 100 mg/ml of each streptomycin sulfate and chlorotetracycline, and incubated at 21 °C in the dark until axenic cultures were obtained. Initially, appressed white- to- pale gray mycelia were formed that turned light pinkish-orange with age (Fig. 2A). Conidia (Fig. 2B-C) were single-celled, hyaline, and cylindrical- to- fusiform with acute ends, and were similar to Colletotrichum fioriniae (Damm et al. 2012). Conidia measured 8.9 ± 1.3 µm long and 3.3 ± 0.6 µm wide (N=40). Genomic DNA was isolated with a Phire Direct Plant PCR kit (Thermo FisherScientific, Waltham, MA). The partial beta-tubulin (TUB2) gene, chitin synthase 1 (CHS-1) gene, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene, and the internal transcribed spacer (ITS) region of ribosomal DNA were amplified with primers T1/BT2B, CHS-354R/CHS-79F, GDF1/GDR1, and ITS1/ITS4, respectively and sequenced (Damm et al. 2012). The resulting sequences were submitted to GenBank (TUB2, ON036471; CHS-1, ON036472; GAPDH, ON036470; and ITS, ON008206). Consensus sequences had 100% identity with C. fioriniae type culture CBS 128517 accessions JQ949943 (TUB2), JQ948953 (CHS-1), JQ948622 (GAPDH), and MH865005 (ITS rDNA). Because H. verticillatus is endangered, and the scarcity of available plant material, Koch's postulates were performed using a detached leaf assay (Boggess et al. 2022). Six healthy leaves were surface-sterilized using the previously described protocol, longitudinally bisected, and placed on 1.5% water agar in three 15 × 100 mm petri dishes. Three half leaves were inoculated with sterile, 5 mm-diameter PDA plugs (controls). The remaining three leaves were inoculated with 5 mm-diameter PDA plugs of C. fioriniae and incubated as described previously. After ten days, necrotic lesions developed on leaves inoculated with C. fioriniae and were similar to the initially observed lesions on plants. Lesions did not develop on control leaves. Colletotrichum fioriniae was re-isolated from lesions using the previously described protocol. The disease does not appear to cause mortality of H. verticillatus and does not require control measures but does reduce the aesthetic value of the plant. To the best of our knowledge, this is the first report of C. fioriniae infecting H. verticillatus in the United States.

Effects of arbuscular mycorrhizal fungi on the nitrogen distribution in endangered Torreya jackii under nitrogen limitation.

MAIN CONCLUSION: Arbuscular mycorrhizal fungi regulated the distribution of nitrogen in the leaves, thereby facilitating the adaptation of the endangered plant Torreya jackii to a low-nitrogen environment. Rhizophagus irregularis was inoculated into sterilized soil to investigate its impact on the distribution ratio of leaf nitrogen in cell wall proteins, cell membrane proteins, water-soluble proteins, and photosynthetic systems which includes the carboxylation system (PC), energy metabolism (PB), and light-harvesting system in the endangered species Torreya jackii. The results showed that R. irregularis reduced the specific leaf weight and the distribution ratio of nitrogen in cell wall proteins in the leaves of T. jackii, whereas it enhanced the distribution ratio of nitrogen in cell membrane proteins and water-soluble proteins. R. irregularis enabled more nitrogen uptake for growth by decreasing the distribution of nitrogen to the structural substances. At low-nitrogen levels, inoculation with R. irregularis improved the plant height (18.78 ~ 36.04%), shoot dry weight (50.53 ~ 64.33%), total dry weight (42.86 ~ 52.82%), maximal net photosynthetic rate (Pmax) (16.83 ~ 20.11%), photosynthetic nitrogen use efficiency (PNUE) (40.01 ~ 43.14%), PC (33.56 ~ 38.59%) and PB (29.08 ~ 34.02%). However, it did not substantially affect the leaf nitrogen content per unit area or the leaf nitrogen content per unit mass. Moreover, Pmax exhibited a significant positive correlation with PC and PB, and all three parameters showed a significant positive correlation with the PNUE, thereby revealing that R. irregularis increased the photosynthetic capacity and PNUE of T. jackii through boosting PC and PB.

Anti-neuroinflammatory diterpenoids from the endangered conifer Podocarpus imbricatus.

Ten diterpenoids including three new abietanes (1-3) were isolated from the twigs and needles of Podocarpus imbricatus, an endangered conifer growing in a Cantonese garden. The new structures were established by means of spectroscopic methods. Among the isolates, 3ß-hydroxy-abieta-8,11,13-trien-7-one (5), decandrin G (6), and 7,15-pimaradien-18-oic acid (8) showed significant anti-neuroinflammatory activities by inhibiting the overproduction of nitric oxide (NO) in lipopolysaccharide (LPS)-stimulated murine BV-2 microglial cells, with IC50 values of 3.7, 11.1, and 4.5 µM, respectively.

Phytochemical attributes of endemic endangered primrose (Primula heterochroma Stapf.) accessions grown in Iran.

Primula heterochroma is indigenous to Caspian coast forests in the north of Iran. Total phenols, total flavnoids, total carotenoids and antioxidant capacity of 50 P. heterochroma accessions were investigated. The highest total phenol (1272.31 mg GA equivalent/100 g fresh weight) and total flavonoids (615 mg catechin/100 g fresh weight) were observed in G5 accession from Saravan. The highest antioxidant activity was observed in G14 accession (73.03 %) from Kacha, followed by G2 accession (69.75 %) and G5 accession (66.84 %) from Saravan. The results of HPLC analysis showed that quercetin-3-glucoside was the major phenolic compound widely found in these accessions followed by chlorogenic acid. There was a linear relationship between the antioxidant capacities and the total phenols and total flavonoid. Inversely, there was no statistically significant correlation between total carotenoid and antioxidant activity. Based on the path coefficient analysis, the maximum direct effect on antioxidant was observed in total phenols (0.908). In addition, the cluster analysis based on Euclidean distance with Unweighted pair-group method using arithmetic average (UPGMA) method separated the accessions into four main groups. Our results supported that Iranian wild primrose accessions possess valuable antioxidant properties for therapeutic and potential medicinal use.

A high-frequency in vitro multiplication, micromorphological studies and ex vitro rooting of Cadaba fruticosa (L.) Druce (Bahuguni): a multipurpose endangered medicinal shrub.

An efficient and reproducible in vitro propagation protocol has been established for Cadaba fruticosa (L.) Druce. Surface-sterilized nodal stem segments of mature plant were used as explants for culture establishment. Multiple shoots were optimally differentiated from the nodal stem explants through bud breaking on Murashige and Skoog (1962) medium containing 3.0 mg l(-1) benzyladenine (BA). The effect of different plant growth regulators and minerals were studied on different stages of micropropagation procedure (i.e., explant establishment, shoot multiplication/growth and ex vitro rooting). Additionally, for enhancing shoot multiplication during subculture, MS medium was modified (MMS) with higher levels of magnesium, potassium and sulphate ions. Out of these, MMS3 medium containing 0.25 mg l(-1) each of BA and Kin (N6-furfuryladenine), with 0.1 mg l(-1) NAA (α-naphthalene acetic acid) was found the best for shoot multiplication (42.45 ± 3.82 per culture vessel). The in vitro regenerated shoots were rooted under ex vitro conditions on treating the shoot base with 500 mg l(-1) of IBA (indole-3 butyric acid) for 3 min on sterile Soilrite®. The ex vitro rooted plants were hardened in the greenhouse and transferred to the field with ≈85 % survival rate. There were not any visual differences between wild and micropropagated plants in the field, although the later underwent significant changes during acclimatization. Micromorphological changes on leaf surface characters from in vitro to acclimatized plantlets were studied in terms of development of glandular trichomes, changes in vein spacing and vein structure in order to understand the nature of plant responses towards environmental conditions. The method developed and defined can be applied for commercial cultivation, which may be important for extraction of bioactive compounds and may facilitate conservation of this multipurpose endangered medicinal shrub.

Presenting Eco-Anatomical Data for Saponaria jagelii, a Species on the Edge of the Blade.

The seeds, roots, leaves, flowers and fruits of the critically endangered (CR) species Saponaria jagelii Phitos & Greuter (Caryophyllaceae) were studied. The morphology of the seeds was investigated with scanning electron microscopy. The seeds were imbibed, germinated and developed into young plants. These plants, along with strictly selected wild-growing plants, were used for optical microscopic observations. The leaves and flowers were observed with scanning electron microscopy as well. At least two types of active glandular trichomes were detected on both the leaves and the calyxes of the flowers. The structures of the primary and secondary roots were also investigated. The roots turned into secondary structures very quickly and very close to the root tip. Light microscopy and histochemical reagents were employed to detect secondary metabolites of interest in the leaves. All the metabolites detected were already reported to be synthesized in stressed plants. Distribution data are presented. Conservation actions based on the habitat morphology and the human activities within it, such as the limitation of beach access during the seed-dispersing period and the prohibition of vehicle usage, are recommended in order to protect this tolerant yet severely stressed plant species.

Leaf functional traits of Parrotia subaequalis from different environments in eastern China.

Functional traits are important in understanding how plants respond and adapt to their immediate environment. Parrotia subaequalis is a highly endangered arbor species found throughout eastern China, primarily inhabiting hillsides and valleys, yet, little is known about the variation in leaf traits across these environments. In the present study, we tested this by comparing leaf surface area, leaf weight, leaf length, leaf symmetry and leaf mass per unit area, as well as the relationship between leaf traits and environmental factors and the scaling relationship between leaf surface area versus leaf dry mass. We observed significant differences in leaf surface area, weight, and length among the population sites, and these variables were strongly affected by environmental factors, especially high mean annual temperatures in hillside habitats and high mean annual precipitation in valley habitats. The scaling exponents remained numerically variant among the 10 populations, with different slopes greater than 1.0, and the scaling exponents increased significantly with hillside habitats. These metrics correlated with soil thickness associated with different habitat types. The areal ratio (AR) values in all populations deviated from 1, indicating that the two lamina sides were asymmetrical. The standardized symmetry index (SI) values displayed significant variation, especially in leaves from hillside habitats with a high degree of asymmetry. Collectively, our findings demonstrated that leaf functional traits exhibit considerable variability in response to different environmental contexts and provide valuable reference data that could be useful for conserving this endangered species.

Monitoring data on the effect of domestic livestock and rabbits on Androcymbiumeuropaeum (Lange) K. Richt. and its xerophytiques pastures for thirteen years.

Background: Dataset of annual monitoring of herbivory effects on the conservation status of the endangered species Androcymbiumeuropaeum (Lange) K. Richt and its associated plant communities is presented in this manuscript. This dataset encompasses the annual monitoring of herbivory effects on the conservation status of the endangered species Androcymbiumeuropaeum. Since 2010, the SERPAM Department (Service of Evaluation, Restoration and Protection of Mediterranean Agrosystems) at the Zaidin Experimental Station, belonging to the Spanish National Research Council (CSIC-EEZ), has conducted annual sampling to assess the impact of both domestic and wild livestock, specifically rabbits, on the pastures where A.europaeum lives. The study consisted of a randomised block design, implementing three distinct treatments to evaluate different management strategies: (1) rabbit and domestic herbivory, (2) exclusion of domestic livestock and (3) exclusion of rabbits and domestic livestock. Within each treatment, two types of monitoring were conducted. Firstly, the abundance of A.europaeum was estimated by counting individuals within 50 cm x 50 cm quadrats. Secondly, plant species diversity was assessed along 2-m long transects using the modified Point-Quadrat method. The research was conducted within the Cabo de Gata-Níjar Natural Park in southern Spain, specifically in the Amoladeras Nature Reserve in Almería. New information: The dataset contains information spanning from 2010 to 2023, providing valuable insights into the annual monitoring of herbivory effects on the conservation status of A.europaeum, contributing to our understanding of the species' interaction with domestic and wild animal in the studied area.

Prediction of the Potential Distribution of the Endangered Species Meconopsis punicea Maxim under Future Climate Change Based on Four Species Distribution Models.

Climate change increases the extinction risk of species, and studying the impact of climate change on endangered species is of great significance to biodiversity conservation. In this study, the endangered plant Meconopsis punicea Maxim (M. punicea) was selected as the research object. Four species distribution models (SDMs): the generalized linear model, the generalized boosted regression tree model, random forest and flexible discriminant analysis were applied to predict the potential distribution of M. punicea under current and future climates scenarios. Among them, two emission scenarios of sharing socio-economic pathways (SSPs; i.e., SSP2-4.5 and SSP5-8.5) and two global circulation models (GCMs) were considered for future climate conditions. Our results showed that temperature seasonality, mean temperature of coldest quarter, precipitation seasonality and precipitation of warmest quarter were the most important factors shaping the potential distribution of M. punicea. The prediction of the four SDMs consistently indicated that the current potential distribution area of M. punicea is concentrated between 29.02° N-39.06° N and 91.40° E-105.89° E. Under future climate change, the potential distribution of M. punicea will expand from the southeast to the northwest, and the expansion area under SSP5-8.5 would be wider than that under SSP2-4.5. In addition, there were significant differences in the potential distribution of M. punicea predicted by different SDMs, with slight differences caused by GCMs and emission scenarios. Our study suggests using agreement results from different SDMs as the basis for developing conservation strategies to improve reliability.

Chromosome-level genome assembly of an endangered plant Prunus mongolica using PacBio and Hi-C technologies.

Prunus mongolica is an ecologically and economically important xerophytic tree native to Northwest China. Here, we report a high-quality, chromosome-level P. mongolica genome assembly integrating PacBio high-fidelity sequencing and Hi-C technology. The assembled genome was 233.17 Mb in size, with 98.89% assigned to eight pseudochromosomes. The genome had contig and scaffold N50s of 24.33 Mb and 26.54 Mb, respectively, a BUSCO completeness score of 98.76%, and CEGMA indicated that 98.47% of the assembled genome was reliably annotated. The genome contained a total of 88.54 Mb (37.97%) of repetitive sequences and 23,798 protein-coding genes. We found that P. mongolica experienced two whole-genome duplications, with the most recent event occurring ~3.57 million years ago. Phylogenetic and chromosome syntenic analyses revealed that P. mongolica was closely related to P. persica and P. dulcis. Furthermore, we identified a number of candidate genes involved in drought tolerance and fatty acid biosynthesis. These candidate genes are likely to prove useful in studies of drought tolerance and fatty acid biosynthesis in P. mongolica, and will provide important genetic resources for molecular breeding and improvement experiments in Prunus species. This high-quality reference genome will also accelerate the study of the adaptation of xerophytic plants to drought.

Spatial heterogeneity analysis of matching degree between endangered plant diversity and ecosystem services in Xishuangbanna.

Biodiversity and ecosystem services (ESs) are closely linked. Human activities have caused critical damage to the habitat and ecosystem function of organisms, leading to decline in global biodiversity and ecosystem services. To ensure sustainable development of local ecological environments, it is critical to analyze the spatial matching degree of biodiversity and ESs and identify ecologically vulnerable areas. Taking Xishuangbanna, southern China, as an example, we constructed a pixel-scale matching degree index to analyze the spatial matching degree of endangered plant diversity (EPD) and four ESs and classified the matching degree into low-low, low-high, high-low, and high-high four types. The results revealed a mismatch relationship of EPD and ESs in more than 70% of areas. Under the influence of altitude and land use/land cover (LULC) type, the matching degree of EPD and ESs showed obvious spatial heterogeneity. In low-altitude areas in the south of Xishuangbanna, EPD and ESs mainly showed mismatch, while high-altitude areas in the west had a better match. Natural forest was the main land cover in which EPD and ESs showed high-high match and its areal proportion was much larger than that of rubber plantation, tea plantation, and cropland. Our findings also stress the need to concentrate conservation efforts on areas exhibiting a low-low match relationship, indicative of potential ecological vulnerability. The pixel-scale spatial matching degree analysis framework developed in this study for EPD and ESs provides high-resolution maps with 30 m × 30 m pixel size, which can support the implementation of ecological protection measures and policy formulation, and has a wide range of applicability. This study provides valuable insights for the sustainable management of biodiversity and ESs, contributing to the strengthening of local ecological environment protection.

High genetic diversity and low differentiation of Michelia coriacea (Magnoliaceae), a critically endangered endemic in Southeast Yunnan, China.

Michelia coriacea, a critically endangered tree, has a restricted and fragmented distribution in Southeast Yunnan Province, China. The genetic diversity, genetic structure and gene flow in the three extant populations of this species were detected by 10 inter-simple sequence repeat (ISSR) markers and 11 simple sequence repeat (SSR) markers. Examination of genetic diversity revealed that the species maintained a relatively high level of genetic diversity at the species level (percentage of polymorphic bands) PPB = 96.36% from ISSRs; PPL (percentage of polymorphic loci) = 95.56% from SSRs, despite several fragmental populations. Low levels of genetic differentiation among the populations of M. coriacea were detected by Nei's G(st) = 0.187 for ISSR and Wright's F(st) = 0.090 for SSR markers, which is further confirmed by Bayesian model-based STRUCTURE and PCoA analysis that could not reveal a clear separation between populations, although YKP was differentiated to other two populations by ISSR markers. Meanwhile, AMOVA analysis also indicated that 22.84% and 13.90% of genetic variation existed among populations for ISSRs and SSRs, respectively. The high level of genetic diversity, low genetic differentiation, and the population, structure imply that the fragmented habitat and the isolated population of M. coriacea may be due to recent over-exploitation. Conservation and management of M. coriacea should concentrate on maintaining the high level of genetic variability through both in and ex-situ conservation actions.

The complete chloroplast genome of Iris speculatrix Hance, a rare and endangered plant native to Hong Kong.

Iris speculatrix is a rare and endangered plant first discovered in and native to Hong Kong. The whole chloroplast genome of I. speculatrix is 152,368 bp in length. It contained a large single copy region (82,003 bp), a small single copy region (17,941 bp), and two inverted repeats (26,212 bp). Phylogenetic analysis of 17 species of Iridaceae was conducted. I. speculatrix was found to be sister to a group of 12 Iris species, including I. setosa, I. lacteal, and I. uniflora. The sequenced chloroplast whole genome would be useful to understand the phylogeny and to conservation of I. speculatrix.

In Vitro Propagation, Genetic Assessment, and Medium-Term Conservation of the Coastal Endangered Species Tetraclinis articulata (Vahl) Masters (Cupressaceae) from Adult Trees.

Tetraclinis articulata (Vahl) Masters is an endangered tree growing in coastal and arid environments that is widely exploited by the timber and resin industry, among other applications. In this context, the use of in vitro techniques is highly encouraged for its propagation. We present a protocol for micropropagation using twigs from adult trees as a source of explants. The Schenk and Hildebrandt basal medium (SH) supplemented with 30 g L-1 sucrose, 6.5 g L-1 plant agar, 4.0 mg L-1 6-benzyladenine (BA), and 0.05 mg L-1 1-naphthaleneacetic acid (NAA) provided the optimum multiplication rate (90.48 ± 9.52 explants with basal shoots and 2.58 ± 0.29 basal shoots per explant). Application of activated charcoal (AC) or ½ Knop solution in a liquid overlay produced significantly longer shoots. Supplementation of solid media with indole-3-butyric acid (IBA) or NAA gave low rooting percentages (<17%). Addition of 0.9 g L-1 AC improved rooting (40%) but rooting performance was optimal (66.7%) after a pulse treatment consisting of 4 h immersion in liquid SH medium without growth regulators, followed by 8 weeks of cultivation. Rooted microplants were successfully acclimatized (93.33%) in a peat moss and vermiculite mixture (1:1 v/v ratio). The genetic stability of the in vitro regenerated plantlets was confirmed using the randomly amplified polymorphic DNA (RAPD) technique. Explant survival and growth remained higher than 90% after 28 weeks of cold storage at both 4 °C and 10 °C. The protocol presented here allows for largescale T. articulata production and could be applied for both ex situ conservation strategies and industrial purposes.

Intraspecific and sex-dependent variation of leaf traits along altitude gradient in the endangered dioecious tree Taxus fuana Nan Li & R.R. Mill.

Plant intraspecific trait variation (ITV) including sex-dependent differences are matters of many ecological consequences, from individual to ecosystem, especially in endangered and rare species. Taxus fuana is an endangered dioecious species with small and isolated populations endemic to the Himalayas region. Little is known about its trait variation between sexes, and among populations. In this study, 18 leaf traits from 179 reproductive trees (males and females) along the altitude (2600-3200m a.s.l.) of the T. fuana populations distributed in Gyirong County, Tibet, China, were measured. ITV and sources of variation in leaf traits were assessed. The relationship between leaf traits of males and females and altitude was analyzed separately. Variations in leaf traits of T. fuana ranged from 3.1% to 24.2%, with the smallest in leaf carbon content and the largest in leaf thickness to area ratio. On average 78.13% of the variation in leaf traits was from within populations and 21.87% among populations. The trends in leaf width, leaf nitrogen to phosphorus ratio, leaf carbon to nitrogen ratio, leaf carbon isotope ratio, and leaf nitrogen isotope ratio in relation to altitude were the same for males and females. Leaf length to width ratio varied significantly with altitude only in males, while leaf phosphorus content, leaf nitrogen content, and leaf carbon to phosphorus ratio varied significantly with altitude only in females. The correlation coefficients of most leaf traits of females with altitude were larger than that of males. In the relationship between leaf traits, there was a high similarity among males and females, but the altitude accounted for more explanation in females than in males. Our results suggested that the variation in leaf traits of T. fuana was small and did not dominate the interspecific competition in the local communities. Adaptation to the altitude gradient of T. fuana might be through altering nutrient storage processes and water use efficiency. Adaptation of male and female T. fuana to environmental changes showed differences, where the males were more tolerant and the females responded greatly to altitude. The differences in adaptation strategies between male and female T. fuana may be detrimental to the maintenance of their populations.

Isolation and characterization of microsatellite loci for Hibiscus aridicola (Malvaceae), an endangered plant endemic to the dry-hot valleys of Jinsha River in Southwest China.

Hibiscus aridicola (Malvaceae) is an endangered ornamental shrub endemic to the dry-hot valleys of Jinsha River in southwest China. Only four natural populations of H. aridicola exist in the wild according to our field investigation. It can be inferred that H. aridicola is facing a very high risk of extinction in the wild and an urgent conservation strategy is required. By using a modified biotin-streptavidin capture method, a total of 40 microsatellite markers were developed and characterized in H. aridicola for the first time. Polymorphisms were evaluated in 39 individuals from four natural populations. Fifteen of the markers showed polymorphisms with two to six alleles per locus; the observed heterozygosity ranged from 0.19 to 0.72. These microsatellite loci would be useful tools for population genetics studies on H. aridicola and other con-generic species which are important to the conservation and development of endangered species.

Begonia catbensis (sect. Coelocentrum, Begoniaceae), a new species from northern Vietnam.

Begonia catbensis, a new species in Begonia sect. Coelocentrum is described and illustrated. The new species was discovered in lowland limestone hills at Cat Ba National Park and can be easily distinguished from all its congeners by having dendritic hairs on the petiole, adaxial veins and stipules, fimbriate bracts and bracteoles, dense conical bullae on the upper surface of the leaf blade, two tepals in the pistillate flowers and a glabrescent ovary with verrucose wings. Based on IUCN Criteria, the species is currently assessed as "Endangered" (D).

The complete chloroplast genome of Endangered species Aristolochia delavayi Franch. (Aristolochiaceae) in Southwestern China.

The complete chloroplast genome of Aristolochia delavayi was determined in this study. The chloroplast genome consists of 160,344 bp, with a typical circular structure including a pair of inverted repeats of 25,454 bp separated by a large single-copy region and a small single-copy region of 89,502 and 19,795 bp, respectively. The plastome contains 130 genes, including 85 protein-coding genes, eight rRNA genes, and 37 tRNA genes. Further phylogenetic analyses were conducted using 12 complete plastomes of Aristolochia. These data support a close relationship between Aristolochia delavayi and Aristolochia tubiflora.