25 research outputs found

    Geographical variation in morphological leaf traits of Huperzia serrata (lycopodiaceae) from Vietnam

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    Morphological leaf traits can be used to assess adaptive responses of plants to environmental conditions. To assess how the representation of Huperzia serrata leaf traits, such as leaf length (LL), leaf width (LW) and leaf area (LA) response to changes in mean annual temperature (MAT), sunshine duration (SuH), mean annual precipitation (MAP), air humidity (Hu), intraspecific variation of the morphological leaf traits of the species was analyzed along a geographical gradient of Vietnam. The results showed that among the three populations at the three sites, leaf sizes increased with MAT and MAP. Huperzia serrata, climatic factors, morphological leaf traits, Vietnam.

    CAMELLIA QUYNHII (THEACEAE, SECT. STEREOCARPUS), A NEW YELLOW SPECIES FROM THE CENTRAL HIGHLANDS, VIETNAM

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    Camellia quynhii is described and illustrated as a new species of section Stereocarpus (Pierre) Sealy from 12th village, Vu Bon Commune, Krong Pak District, Dak Lak Province. C. quynhii resembles C. dormoyana (Pierre) Sealy but differs in several morphological characteristics: sepals 6–7; petals about 12–15; filaments tomentose at the base; style 3(–4), basally united; capsule 3(–4) locular, 2–6 seeds in each locule. Information on its phenology, distribution, ecology, and conservation status is also provided.Camellia quynhii is described and illustrated as a new species of section Stereocarpus (Pierre) Sealy from 12th village, Vu Bon Commune, Krong Pak District, Dak Lak Province. C. quynhii resembles C. dormoyana (Pierre) Sealy but differs in several morphological characteristics: sepals 6–7; petals about 12–15; filaments tomentose at the base; style 3(–4), basally united; capsule 3(–4) locular, 2–6 seeds in each locule. Information on its phenology, distribution, ecology, and conservation status is also provided

    Genetic diversity of Panax vietnamensis var. fuscidiscus K. Komatsu, s. Zhu & S.Q. cai population in western north of vietnam detected by inter simple sequence repeat markers

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    Panax vietnamensis var. fuscidiscus is a precious medicinal plant which was recently discovered in Sin Ho and Muong Te district, Lai Chau province of Vietnam. Over exploitation of the species in the native habitat poses a serious threat to its existence. Adequate information on the nature and the extent of genetic diversity in this important species is required for developing suitable strategy for its conservation. In this study, inter simple sequence repeat markers were employed to investigate the genetic diversity and variability of 46 individuals belonging to a naturally distributed population of this variety in Vietnam. Genetic diversity at the population level was high (He = 0.2300, I = 0.3665, and PPB = 96.98 %). The group of mature individuals possessed the higher genetic diversity (HeO = 0.2291, IO = 0.3563, and PPBO = 84.34 %) as compared to group of young individuals (HeY = 0.2086, Iy = 0.3291, and PPBY = 81.5 %). The intergroup gene differentiation was high (GST = 0.0499) with the genetic distance among groups was 0.0298. The similarity coefficient among mature individuals was more moderate (Maximum = 0.873, Minimum = 0.614 and Average = 0.741) than among young individuals (Maximum = 0.916, Minimum = 0.596 and Average = 0.759). Otherwise, the number of discovered individuals was small, distribution area is narrow habitats, and the population showed the reduction in genetic diversity due to the human affects in the habitat and over-exploitation. Results on genetic diversity and variability showed that the investigated population has coped with the risk of decline and needed to be protected

    AN UPDATED CHECKLIST AND COMMENTS FOR SECTION PIQUETIA (CAMELLIA, THEACEAE)

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    New Camellia species in section Piquetia have recently been discovered. It is necessary to enumerate the number of species and update the specific characteristics of this section. Based on the study of more than 30 pieces of literature and a large number of specimens, a total of 15 species belonging to section Piquetia, including two new species, are identified. A taxonomic key to all species is provided, and typical characteristics of the section are also discussed. Information on the distribution, ecology, and conservation status of each species, as well as notes on the differences between closely related species, is also provided.

    . In vitro propagation of the new orchid Dendrobium trankimianum T. Yukawa

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    Dendrobium trankimianum T. Yukawa is a beautiful, endemic orchid of Vietnam, a new species with a first - published description in 2004. It is very rare and expected to be added to the IUCN Red List status - CR. In vitro studies of orchid D. trankimianum T. Yukawa were conducted in order to conserve and increase the genetic pool of this precious wild orchid species. The results showed that full-strength MS medium supplemented with 2.0 mg/L BA and 0.5 mg/L NAA (10.24 PLBs/explant; 90.11% explants formed PLBs) or full-strength MS medium supplemented with 1.5 mg/L TDZ and 0.5 mg/L NAA (14.11 PLBs/explant; 92.06% explants formed PLBs) were the most suitable for protocorm formation. For subculture, suitable growth of shoots were obtained on full-strength MS medium supplemented 1.5 mg/L BA (22.35 shoots/explant; shoots length of 1.96 cm) and full-strength MS medium supplemented with 60 g ripe banana per liter (25.11 shoots/explant; shoots length of 2.12 cm). The shoots in vitro were transferred to half-strength MS supplemented with different concentrations of IAA, IBA and NAA to investigate root formation. The best rooting occurred at 0,5 mg/L NAA (7.91 roots/shoot; root length of 4.01 cm; 98.51% root formation). The plantlets with uniform growth were planted on different substrate: Eco clean soil, Coconut fiber, Fern fiber, 50% Rice husk in combination with 50% Eco clean soil for research the most suitable substrate. After 60 days of transplantion and acclimatization, the result showed that Fern fiber was suitable substrate for plantlet growth in a nursery garden (8.0 roots/ explant; root length of 5.5 cm; survival rate of 93.29%)

    GLUCOSIDES AND UREA DERIVATIVES FROM THE SEEDS OF SCAPHIUM MACROPODUM (MIQ.) BEUMÉE

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    Five known compounds {carbonylbis[imino(6-methyl-3,1-phenylenel)]}bis[carbamic acid] dimethyl ester (1), (1'R,3'S,5'R,8'S,2E,4E-dihydrophaseic acid) 3'-O-beta-D-glucopyranoside (2), 3-methylbutan-1-ol beta-D-glucopyranoside (3), astragalin (4) and daucosterol (5) were isolated from the methanol extract of the seeds of Scaphium macropodum (Miq.) Beumée. The structures of the isolated compounds were elucidated by the spectroscopic methods including NMR and MS, and also by comparison with the literature data. Compounds 1-3 were isolated from this plant for the first time

    Hymenorchis phitamii (Orchidaceae)

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    Hymenorchis phitamii – new species for science discovered in southern Vietnam described and illustrated. From most closely related H. javanica it differs in emarginate orbicular lip and nearly straight (or hardly serrulate) tepals and leaves. The first record of the genus Hymenorchis in mainland Asia represents new remarkable addition to the orchid flora of Vietnam, as well as floras of Indochina and mainland Asia

    Yersinochloa nghiana, a new species (Poaceae, Bambusoideae, Bambuseae) from southern Vietnam

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    Yersinochloa nghiana sp. nov. from Vietnam is described and illustrated. It is found from southern Vietnam, where it occurs at an elevation of 1130 m in Braian Mountain, Di Linh District, Lam Dong Province. This new species is distinguished from a similar species, Yersinochloa dalatensis, by culm nodes with a thick swollen patella, culm leaf blades erect, auricles conspicuous, margins bearing long hairs, palea dorsal view showing rachilla extension and rudimentary floret at the apex and lodicules bifid at the base

    The environmental and economic impact of the emissions trading scheme (ETS) in Vietnam

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    This study aims to fill a gap in the literature by examining the impacts of an emissions trading scheme (ETS) in Vietnam, as the policy has been discussed for a decade in the country but the likely impacts on the economy and different sectors are still unidentified. The simulations are carried out in a global energy computable general equilibrium (CGE) model, an extension of the GTAP-E model, which treats Vietnam as a country region. Results show that restricting the number of industrial sectors in the emissions trading market substantially affects the country's economy with a decline in real GDP by 4.57%. However, the country experiences much smaller adverse impacts (e.g., real GDP declines by 1.78%) when all industries participate in the emissions trading market. In either case of the ETS design, the coal mining, manufacturing, transportation, and electricity sectors are highly adversely affected; however, the crude oil and natural gas extraction sectors would experience expansion in their production levels due to substitutions for coal. In general, under the policy the emission levels from burning fossil fuels decline at significant rates, particularly from the electricity generation sector.</p
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