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Latest development in agarwood creates better use in different fields of life sciences. With the development of social economy, China's agarwood industry has developed rapidly in recent years and has gradually become a characteristic industry of local pillar industries. Due to the particularity of agarwood and its precious rarity, it is the most treasured treasure of collection. The agarwood collection is a fashion and the best way to preserve value, both ancient and modern. New advancement was discussed in advance use of chemical constituents of Aquilaria siwasis mainly include flavonoids, benzophenones, lignans, phenyl propanoids, terpenoids, alkaloids, steroids, phenolic compounds. Some of them have anti-tumor, antibacterial, anti-inflammatory, analgesic, and laxative activities antibacterial constituents isolated from Aquilaria sinensis were reviewed, the latest uses of agarwood for religious as well as medical treatment and the biological activities of some compounds were also introduced. These would provide scientific basis for development and utilization of A.

Caesalpinia sappan Linnaeus is a great tree of Fabaceae. It is mainly distributed in the Southern provinces of China and Southeast Asian countries. It can be used to extract dyes. The heartwood has dyestuff and medicinal value. There is no study on the genome of C. sappan so far. Here, we report and characterize the complete plastid genome sequence of C. sappan in an order to provide genomic resources useful for promoting its conservation. The complete chloroplast genome of C. sappan is 160,176 bp in length with a typical quadripartite structure, consisting of a large single-copy region (LSC, 89,710 bp), a single-copy region (SSC, 18,357 bp), and a pair of inverted repeats (IRs, 26,054 bp). There are 129 genes annotated, including 84 unique protein-coding genes, eight unique ribosomal RNA genes, and 37 transfer RNA genes. The overall G/C content in the plastome of C. sappan is 36.0%. The complete plastome sequence of C. sappan will provide a useful resource for the conservation genetics of this species as well as for phylogenetic studies in Apocynaceae.

N6-methyladenine (6mA) DNA modification has been detected in several eukaryotic organisms, where it plays important roles in gene regulation and epigenetic memory maintenance. However, the genome-wide distribution patterns and potential functions of 6mA DNA modification in woodland strawberry (Fragaria vesca) remain largely unknown. Here, we examined the 6mA landscape in the F. vesca genome by adopting single-molecule real-time sequencing technology and found that 6mA modification sites were broadly distributed across the woodland strawberry genome. The pattern of 6mA distribution in the long non-coding RNA was significantly different from that in protein-coding genes. The 6mA modification influenced the gene transcription and was positively associated with gene expression, which was validated by computational and experimental analyses. Our study provides new insights into the DNA methylation in F. vesca.

Hainan Island harbours an extraordinary diversity of Gesneriaceae with 14 genera and 23 species, amongst which two species and one variety are recognised in the genusOreocharis. These threeOreocharistaxa are all Hainan-endemics and show a complex geographical distribution pattern with considerable morphological intermixtures. In this study, we combined DNA (nuclear ITS sequences and cpDNAtrnL-trnF andycf1b) to evaluate genetic delimitation for 12Oreocharispopulations from the island, together with morphological similarity analysis using 16 morphological traits. The results showed HainanOreocharistaxa were monophyletic with relative low genetic diversity within populations, highly significant genetic differentiation amongst populations and a significant phylogeographical structure. The 12 populations formed three genetically distinct groups, roughly correspondent to the currently recognised two species and one unknown lineage. The PCA analyses of morphological traits indicate three distinctive groups, differing mainly in petal colour and corolla shapes. The roles of river and mountain isolations in the origin and distribution of these three lineages are discussed.

BackgroundGene flow in plants via pollen and seeds is asymmetrical at different geographic scales. Orchid seeds are adapted to long-distance wind dispersal but pollinium transfer is often influenced by pollinator behavior. We combined field studies with an analysis of genetic diversity among 155 physically mapped adults and 1105 F1 seedlings to evaluate the relative contribution of pollen and seed dispersal to overall gene flow among three sub-populations of the food-deceptive orchidPhalaenopsis pulcherrimaon Hainan Island, China.ResultsPhalaenopsis pulcherrimais self-sterile and predominantly outcrossing, resulting in high population-level genetic diversity, but plants are clumped and exhibit fine-scale genetic structuring. Even so, we detected low differentiation among sub-populations, with polynomial regression analysis suggesting gene flow via seed to be more restricted than that via pollen. Paternity analysis confirmed capsules ofP. pulcherrimato each be sired by a single pollen donor, probably in part facilitated by post-pollination stigma obfuscation, with a mean pollen flow distance of 272.7 m. Despite limited sampling, we detected no loss of genetic diversity from one generation to the next.ConclusionsOutcrossing mediated by deceptive pollination and self-sterility promote high genetic diversity inP. pulcherrima. Long-range pollinia transfer ensures connectivity among sub-populations, offsetting the risk of genetic erosion at local scales.

A new phenolic derivative (1) and a new dihydrophenanthrene (2) were isolated from the aerial part of Dendrobium hainanense rofe, along with 12 known compounds. The structures of the new compounds ...

Tropical and subtropical ecosystems, especially those found on limestone substrates, are among the most diverse terrestrial habitats in China. However, little is known about patterns of plant diversity, ecology and conservation status within these ecosystems. In this special issue we present five reviews and/or in-depth studies of these tropical Chinese plants and ecosystems that capture current research efforts in tropical China plant ecology.

For species relying on seeds for population regeneration, knowledge on seed germination behaviors in relation to environmental factors is critical in designing species recovery strategy. Dendrobium sinense is an orchid endemic to Hainan Island of China and listed as Endangered by the IUCN Redlist. It reproduces primarily via seeds in its natural habitat. However, how germination is impacted by major environmental factors is poorly known. This study aimed to examine germination success of D. sinense seeds using two approaches, i.e. in situ and ex situ, using host tree barks as germination media. The latter was intended to generate symbiotic seedlings in a simple and economic approach which could be used for reintroduction efforts. In addition, three factors of in situ symbiotic seed germination success, including different sowing time, location (distance from an adult plant), and host tree were investigated. Our results showed that seeds sown ex situ and in situ in July had the highest rates of germination. Seed germination was significantly higher ex situ using bark as medium than in situ. Seeds sown directly on Rhododendron moulmainense, the most common host tree, with naturally occurring conspecific orchids had the highest rate of germination. In contrast, ex situ seeds sown on the bark of Cyclobalanopsis blakeii, a non-host species, had the highest rate of seed germination. In situ a positive correlation was found between the seed germination rate and the distance of the seeds from the adult D. sinense. Based on these results, it is likely seedling recruitments are determined by host tree species, the presence of and the distance from an adult conspecific orchid, which imply the importance of the mycorrhizal fungi, which were not reported here. This study provided important information on the optimal environmental conditions for population augmentation and reintroduction, which can be used as part of the species recovery strategy.

Wrightia laevis Hook. f. is a great tree of Apocynaceae. It is mainly distributed in Southeast provinces of China and Southeast Asian countries. It is a plant that combines dyestuff and economic value. There is no study on the genome of W. laevisso far. Here we report and characterize the complete plastid genome sequence of W. laevis in order to provide genomic resources useful for promoting its conservation. The complete chloroplast genome of W. laevis is 155,274 bp in length with a typical quadripartite structure, consisting of a large single-copy region (LSC, 85,463 bp), a single-copy region (SSC, 18,181 bp) and a pair of inverted repeats (IRs, 25,815 bp). There are 133 genes annotated, including 88 unique protein-coding genes, 8 unique ribosomal RNA genes, and 37 transfer RNA genes. The overall G/C content in the plastome of W. laevis is 38.05%. The complete plastome sequence of W. laevis will provide a useful resource for the conservation genetics of this species as well as for phylogenetic studies in Apocynaceae.

Caesalpinia sappan Linnaeus is a great tree of Fabaceae. It is mainly distributed in the Southern provinces of China and Southeast Asian countries. It can be used to extract dyes. The heartwood has...

Additional file 1: Table S1. Fruit-set in Phalaenopsis pulcherrima following artificial pollination treatments (self- and cross-pollination) and natural (open) pollination Table S2. Number of F1 seedlings for micropropagation, Table S3. Characterization and annealing temperatures (Ta) of 15 microsatellite loci developed for Phalaenopsis pulcherrima, .

Hainan Island harbours an extraordinary diversity of Gesneriaceae with 14 genera and 23 species, amongst which two species and one variety are recognised in the genus Oreocharis. These three Oreocharis taxa are all Hainan-endemics and show a complex geographical distribution pattern with considerable morphological intermixtures. In this study, we combined DNA (nuclear ITS sequences and cpDNAtrnL-trnF and ycf1b) to evaluate genetic delimitation for 12 Oreocharis populations from the island, together with morphological similarity analysis using 16 morphological traits. The results showed Hainan Oreocharis taxa were monophyletic with relative low genetic diversity within populations, highly significant genetic differentiation amongst populations and a significant phylogeographical structure. The 12 populations formed three genetically distinct groups, roughly correspondent to the currently recognised two species and one unknown lineage. The PCA analyses of morphological traits indicate three distinctive groups, differing mainly in petal colour and corolla shapes. The roles of river and mountain isolations in the origin and distribution of these three lineages are discussed.

Orchid endophytes harbored in roots may have important interactions with the orchids themselves. However, few studies have demonstrated whether the coexistence of endophytic fungi and bacteria could affect the growth and development of orchid species. Four epiphytic fungi and four epiphytic bacteria were isolated from Dendrobium catenatum, and five “fungi + bacteria” combinations were obtained to dual inoculate with in vitro asymbiotic germinated D. catenatum seedlings. Significant variation was found for the five “fungi-bacteria” combinations on seedlings growth compared with non-inoculated treatment and corresponding single inoculated treatment. Compared with corresponding single inoculation, PY (Pyrenochaeta sp.) + HE2 (Herbaspirillum sp.) showed synergistic effects on increase in fresh weight and lateral root number, additive effects on tiller number and root tip number; EP2 (Epulorhiza sp.) + HE1 (Herbaspirillum sp.) showed synergistic effects on root tip number, additive effects on increase in fresh weight and lateral root number. Three of the combinations, namely PA (Paraphoma sp.) + HE2 (Herbaspirillum sp.), EP2 (Epulorhiza sp.) + EN1 (Enterobacter sp.) and EP2 (Epulorhiza sp.) + EN2 (Enterobacter sp.), gave additive effects but no synergistic effects on seedling growth which suggested the presence of competition for nutrition. PY (Pyrenochaeta sp.) + HE2 (Herbaspirillum sp.) expressed the best promotion than its corresponding single fungi or bacteria inoculation. All dual and single endophytes inoculations showed significant increase in root branching, with only one exception of PA. The study shows that co-inoculation with endophytic fungi and bacteria could be feasible to promote orchid growth. We suggest that not only an understanding of the mycorrhizal biology but also the balance of other various endophytes should be a necessary consideration for orchid conservation in future.

A new phenolic derivative (

The effects of allelochemicals and aqueous extracts from different Pogostemon cablin (Blanco) Benth., Lamiaceae, parts and rhizosphere soil on growth parameters, leaf membrane peroxidation and leaf antioxidant enzymes were investigated in patchouli. P. cablin seedlings were incubated in solutions containing allelochemicals and aqueous extracts from different patchouli parts and its rhizosphere soil at several concentrations. Firstly, the growth parameters were significantly reduced by the highest concentration of leaves, roots and stems extracts (p

Four new bibenzyl derivatives, named dendrosinens A–D (1–4), together with twelve known phenolic compounds were isolated from the whole plant of Dendrobium sinense T. Tang et F. T. Wang, an endemic and endangered orchid in Hainan Island, PR China. Their structures were elucidated by 1D, 2D NMR (HMBC, HMQC, COSY and NOESY), and HREIMS analyses. Bioassay results demonstrated that compounds 5–8 showed cytotoxic activity.

Mirror-image flowers represent a highly specialized pollination system that is normally associated with poricidal anthers and buzz pollination (pollen can be only released from anthers via pollinator vibration). In the Asian endemic Hiptage benghalensis (Malpighiaceae), mirror-image flowers were found with longitudinally dehiscing anthers and such floral syndromes are firstly reported in the family. We investigated the floral biology and frequencies of left- and right-styled flowers of H. benghalensis in Hainan Island, southern China. We conducted pollination manipulations to determine breeding systems and studied the pollination mechanism. We also examined the compositions of the secretions of the calyx gland. Controlled pollinations revealed that H. benghalensis is self-compatible. Left- and right-styled flowers are produced in the same inflorescence and a 1:1 ratio is found at both plant and population levels. Flowers have extremely reflexed petals, zygomorphic corollas and a single but oversized calyx gland. This gland secretes sugars and mainly attracts ants and wasps in both blooming and fruiting periods. Heteranthery is obvious with one large stamen producing more viable pollen than the nine small stamens. All anthers dehisce longitudinally and pollen grains readily adhere to floral visitors without the need of buzz pollination. The unusual association of mirror-image flowers with longitudinal anthers probably reflects an adaptation to local pollen-collecting (but non-buzzing) honeybees such as Apis dorsata. These results indicate that floral syndromes and pollination adaptation in H. benghalensis differ completely from the New World Malpighiaceae and may help to explain evolutionary adaptations of the family during its long-distance dispersals from the New World to Asia. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 173, 764‐774. ADDITIONAL KEYWORDS: calyx gland ‐ enantiostyly ‐ floral conservatism ‐ floral syndromes ‐ Hainan Island ‐ heteranthery ‐ pollination system.

Seven new 2-(2-phenylethyl)chromone derivatives (1-7) including a chlorinated one (4), together with eight known ones (8-15), were isolated from the EtOAc extract of artificial agarwood originating from Aquilaria sinensis (Lour.) Gilg. All structures including the absolute configurations were unambiguously elucidated by spectroscopic (NMR, UV, IR, MS) methods, Mosher's method, and comparison with reported data in the literatures. Among those, compounds 8, 12, and 14 exhibited significant inhibition against α-glucosidase in vitro with IC50 values of 0.15, 0.05, and 0.09 mM, respectively (with acarbose as the positive control; IC50: 0.98 mM). In addition, compounds 3, 9, 11, and 14 showed weak inhibitory activity against AChE; and compounds 12 and 13 displayed weak cytotoxicity against human gastric cell line (SGC-7901) among three types of tested human cancer cell lines (BEL-7402, K562, and SGC-7901).

Global conservation of plant biodiversity on tropical islands is a major priority, as approximately one third of all endangered plant species are insular endemics. Checklists can be an important first step in determining conservation priorities on islands. Hainan, the largest island in the Indo-Burma Biodiversity Hotspot, and therefore an international focus for conservation, has the most extensive and best preserved tropical forests in China. In this study we enumerate the endemic seed plants of Hainan Island. The checklist was prepared by consulting: (1) several bibliographic/taxonomic data base resources, (2) relevant taxonomic treatments and floras, and (3) plant taxonomists who are actively working with Chinese plants. The checklist also contains information concerning conservation status, the occurrence of Hainan endemics in four protected areas on the island, and available molecular phylogenies. An additional checklist of the species that were until recently thought to be endemic to Hainan, but are no longer considered to be, is also presented. In a separate paper in this issue of Botanical Review the patterns of endemism on Hainan Island are discussed.

Hainan, the second largest island of China, has the most extensive and best preserved tropical forests of this country. A network of 68 protected areas (54 of them are terrestrial) provides in situ conservation for the unique ecosystems of the island. We: (1) discuss an updated check-list of seed-plant species that are endemic to Hainan, (2) evaluate the extent to which the endemic flora has been the subject of molecular studies, and (3) investigate the conservation status of these species. We recognize 397 endemic species on the island, 271 of which are reported in the protected areas, and 144 of which have been Red-Listed (85 assigned to the Critically Endangered (40) or Endangered (45) IUCN categories). The families with the highest number of endemics are Rubiaceae (33 species), Lauraceae (27 species), and Poaceae (26 species). The island has only seven endemic genera, all of which are unispecific. Compared with other tropical islands, Hainan has a low number of endemics but our preliminary observations suggest that the island has a highly disharmonic flora when compared with that from the mainland. Nevertheless, most of the major clades of the seed-plant tree of life with representatives in China also have endemic species on the island. We argue that the low levels of endemism reflect the continental nature of Hainan and the fact that several areas of the island have not been fully inventoried. We were unable to find a single molecular systematic study focusing exclusively on the Hainan endemics; however, 24 of the endemic species have been included in phylogenetic studies targeting particular genera or families. Future research/conservation actions for the endemic flora of Hainan should focus in developing: (1) a red-list that assesses all 397 endemic species, (2) comprehensive floristic studies for the protected areas, (3) molecular phylogenetic and conservation genetic studies with a primary focus on the endemics, (4) studies to understand what ecological interactions are important in the biology of the endemic species, and (5) eco-geographical studies to identify Important Biodiversity Zones of endemism within Hainan and therefore potential new protected areas.

A new species, Thrixspermum odoratum X.Q. Song, Q.W. Meng & Y.B. Luo from Hainan Island, south China, is described and illustrated. It belongs in sect. Thrixspermum and is closely related to T. tsii, but differs by having dense and distichous bracts, an irregularly-shaped clump or an erect lamellum at the base of lip, longer midlobe of lip, and fragrant flowers. A key to the five species of sect. Thrixspermum in China is presented. Thrixspermum odoratum is a host-specific epiphyte, being found only on one tree species.

A new species, Gastrodia longitubularis Q.-W. Meng, X.-Q. Song & Y.-B. Luo from Hainan Island, southern China is described and illustrated. This is the first species of Gastrodia recorded from Hainan Island. Diagnostic characters, description, detailed illustration and taxonomic comments are given. This species is closely related to G. gracilis, which is characterized by tuberous rhizome with flesh roots, lax inflorescence and nearly united perianth tube. Gastrodia longitubularis distinctly differs from G. gracilis by having slender, glabrous, long perianth tube, horizontal or slightly downward bending flowers. The habitat was investigated in detail and its conservation status was assessed as a critically endangered EN (B2a, C2a) according to the IUCN threatened category criteria based on data from five years’ observations. The genus Gastrodia R. Br. (Orchidaceae) contains saprophytic orchids distributed in warm areas of Madagascar, tropical Asia, Oceania, Japan and China (Jones 1991, Seifenfaden 1992, Leou 2000). It is a small genus of 16� 31 species, characterized by a fleshy tuber or coralloid underground stem, absence of leaves, union of sepals and petals and two mealy pollinia without caudicles (Dressler 1993, Seifenfaden and Wood 1995, Leou 2000, Chung and Hsu 2006). Despite clear diagnostics and readily recognized characters, most Gastrodia species are unknown to botanists. During a botanical orchid expedition to Hainan Island, southern China, an unknown species of Gastrodia was collected from the tropical mountain rain forest. In general appearance, this species is similar to G. gracilis Blume distributed in Taiwan and Japan, but the morphological anatomy of floral organs and a careful field observation on its habitat have revealed that it is easily distinguished from G. gracilis by having a slender, glabrous, long perianth tube, horizontal or slightly downward bending flowers, and thus represents an undescribed species.

A new phenanthrenequinone, named denbinobin B (1), together with three known phenanthrenes was isolated from the whole plant of Dendrobium sinense T. Tang et F.T. Wang, an endemic and endangered orchid to Hainan Island. The new compound was elucidated using a combination of 1D, 2D NMR (COSY, HMQC, and HMBC) techniques, and HR-ESI-MS analyses. Compound 1 exhibited moderate antibacterial activity against Staphylococcus aureus with the diameter of the inhibition zone of 16.5 mm.

Essential oil produced by patchouli was one of the most important naturally occurring base materials used in the perfume industry, containing various sesquiterpenes. Three different parts (leaves, stems and roots) of Pogostemon cablin (Blanco) Benth., Lamiaceae, were profiled in relation to different maturation phases in this paper, evaluating the variations in content of the major sesquiterpenes in the essential oil. Twelve sesquiterpenes were analyzed by GC-MS throughout the maturity of P. cablin. Patchouli alcohol (37.54%-51.02% in leaves, 28.24%-41.96% in stems and 14.55%-35.12% in roots) was the major sesquiterpene during the maturation of the plant. The average content of several other sesquiterpenes (α-bulnesene, α-guaiene, seychellene, β-humulene and caryophyllene) were higher than 3% among leaves, stems and roots. The content of essential oil, patchouli alcohol, α-bulnesene and several other compounds were highly accumulated at 210 days of maturation after cultivation of P. cablin. Thus, this period was the best moment to exploit the maximum level of these high value-added compounds in P. cablin. Furthermore, our results indicated that the essential oil extracted from leaves of P. cablin has the highest potential to be used in the perfume industry. Keywords: Essential oil, GC-MS, Patchouli alcohol, Pogostemon cablin, Sesquiterpenes