Vietnam Academy of Science and Technology: Journals Online
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Evaluation of genetic diversity and DNA fingerprinting of 19 standard reference rice varieties using SSR markers
Full text linkMolecular markers are advanced-tools for identifying new varieties at DNA levels. According to the International Union for the Protection of New Varieties ofPlants, new breeded varieties need to be tested for the Distinctness, Uniformity and Stability (DUS), before being recognized as the new ones. Traditional DUS criteria based on 62 - 65 morphological and biochemical characteristics, which evaluated on comparison of new varieties with 19 standard reference varieties for traits of interest. Study on the genotypic polymorphism of 19 standard reference rice varieties provides genotypic information of these varieties for the evaluation of new rice varieties based on genotyping analysis. The reference marker set (30 markers) was used to evaluate the genetic diversity and DNA fingerprinting of 19 standard reference rice varieties. The results showed the similarity coefficient of 19 varieties varied from 0.04 to 0.548. At the genetic similarity coefficient of 0.1, the 19 rice varieties divided into two main groups. Group one included 3 varieties: DH1, DH5, DH13. Group 2 included the remaining 16 varieties. Inside group two, phylogenetic tree divided into two main branches at the genetic similarity coefficient of 0.3. Branch 1 includes 5 varieties including DH2, DH6, DH10, DH11 and DH7. The 11 remaining varieties were in the branch 2. The most closely varieties were DH6 and DH10 with the genetic similarity coefficient of 0.548. This study shows that, the standard reference varieties have high uniformity and high genotypic polymorphism, could used for testing new varieties based on genotyping by DNA fingerprinting combining with phenotype
Construction of CRISPR/Cas9 expression vectors habouring gRNA targeted on SLIAA9 gene of tomato
No full textTomato (Solanum lycopersicum) is a nutritious fruit containing many secondary compounds with health benefits. The formation of tomato fruit through fertilization is controlled by auxin through Aux/IAA9 and ARF8 proteins. The mutated SlIAA9 gene leads to the parthenocarpic development of fruit or seedless tomato fruit. Nowadays, the CRISPR/Cas9 genome editing system is becoming increasingly popular in modifying desired genes on plant objects. In this study, gRNAs which target on tomato SlIAA9 gene were designed and inserted into CRISPR/Cas9 vectors. In addition, two strains of A. tumefaciens harboring pRGEB31-IAA9G2 and pRGEB32-IAA9G2 vectors carrying CRISPR/Cas9 expression system towards SlIAA9 gene in tomato were successfully created. The strain of A. tumefaciens harboring pRGEB31- IAA9G2 plasmid was used to develop transgenic tomato plants from Micro-Tom variety. PCR test showed that 5/14 plants had the presence of Cas9 gene in T0 plants. The transgenic plants have a normal morphology in comparation with the controls. The evaluation of mutant efficiency, type, and stability of mutations on the SlIAA9 will be conducted on next-generation plants when the mutations are stable and segregated into descendents
STUDY ON THE HEALTH IMPACT FROM USING BEEHIVE COAL STOVES IN HOUSEHOLDS IN HOAN KIEM, HANOI
No full textThe combustion of biomass and coal significantly contributes to the total health burden due to the emission of gaseous pollutants and particulate matter. To determine the personal exposure related to beehive coal stove cooking in Hanoi, an assessment study on 120 females in three wards (Tran Hung Dao, Phuc Tan and Chuong Duong) were conducted. Personal and ambient concentration of PM2.5 and CO (upwind, near source, far source) were simultaneously measured twice a day at each household by PATS++ equipment developed by Berkeley Air Monitoring group. The concentrations of PM2.5 in three wards were in range of 10-186, 12-441, 9-59, 3-271, and 9-260 µg/m3 while those of CO varied from 100-3000, 300-260000, 200-29000, 300-255000, and 2000-36000 µg/m3, for upwind, near source, far source, indirect exposure and direct exposure samples, respectively. The estimated COHb% for direct exposed group was higher than indirect exposed group in the three wards. Consequently, directly exposed group was suffering a higher risk. All directly exposed respondents and 75% of indirectly ones were experienced COHb% calculated in blood exceeding safe threshold for health of WHO guidelines. There has been increased risk for both exposed group if the coal beehive stove placed indoor. The calculated levels of incremental life cancer risk (ILCR) posed by PM2.5 in the three wards ranged from 1.6E-06 to 3.8E-06 daily, indicating moderate cancer risk to community that should be study further to protect public health
STUDY ON FLUORINATION AND HYDROGENATION IN TRANSPARENT CONDUCTING ZINC OXIDE THIN FILMS
Full text linkFluorination and hydrogenation are known as two methods for enhancing crystalline structural and electrical properties of ZnO material. The ZnO thin films normally require a low resistivity and a high transmittance for using as high-performance transparent electrodes in optoelectronic applications. In this study, we report successful preparation of fluorinated and hydrogenated ZnO thin films (FZO and HFZO) by using d.c. magnetron sputtering technique. The hydrogenation was carried out by depositing the films in hydrogen plasma atmosphere, while a highly-sintered body of ZnO and ZnF2 compound was employed as a sputtering target for the fluorination. The results show that the strong improvements in carrier concentration, mobility and resistivity of the FZO and HFZO films as compared to the pure ZnO films. The carrier concentration increases to 2x1020 cm-3 which is mainly due to the hydrogenation. The effect combination of the fluorination and the hydrogenation is responsibility for enhancing the mobility up to 43 cm2/Vs. These results give rise to two-order reduction in resistivity, from 0.06 Ohm.cm (ZnO) to 7.5x10-4 Ohm.cm (HFZO), which can be a good choice for thin-film electrode application. In addition, the crystalline structure and optical transmission of the films are also discussed
TURBIDITY REMOVAL BY MUCILAGE FROM BASELLA ALBA
Full text linkCoagulation and flocculation are preliminary used in water treatment processes for turbidity removal, using popularily synthetic chemicals with health and environmental concerns. The use of natural flocculants has known to be a promising alteratives for chemical ones due to their environmental friendly behavior. This research investigated turbidity removal efficiency of mucilage extracted from Basella alba - an indigenous species in Vietnam - in the role of a flocculant. The removal efficiency of mucilage was investigated in combination with PAC or Alum on To Lich river water by mean of Jar tests. PAC or Alum alone can remove maximum 97% and 90% turbidity of To Lich river water at its original pH for the sedimentation time of 30 minutes. The combination of mucilage and PAC or Alum increased the efficiencies of turbidity removal and reduced the amount of chemicals needed. The corresponding increases were maximum 7% and 18%, respectively; while the reduction of PAC/Alum used was 75-80%
chemical constituents from methanolic extract of Garcinia mackeaniana leaves and their antioxidant activity
Full text linkA phytochemical investigation of the methanolic extract of Garcinia mackeaniana leaves led to the isolation, and determination of five secondary metabolites, including one benzophenone 4,3',4'-trihydroxy-2,6-dimethoxybenzophenone (1), two flavone C-glucosides vitexin (2) and its 2''-O-acetyl derivative (3), one biflavone amentoflavone (4), and one mono-phenol methyl protocatechuate (5). The chemical structures of these compounds were characterized by the NMR-spectroscopic method. These isolated compounds were isolated from G. mackeaniana species for the first time. Benzophenone derivative 1 has shown to be associated with a significant IC50 value of 14.97±0.8 µg/mL in the DPPH-antioxidant assay
PM2.5-BOUND PAHS IN THE INDOOR AND OUTDOOR AIR OF NURSERY SCHOOLS IN HANOI, VIETNAM AND HEALTH IMPLICATION
Full text link32 daily PM2.5 samples were collected parallelly outdoor and indoor at sixteen nursery schools in Hanoi.15 individual PAHs were analyzed by GC/MS. Mutagenicpotential (MP) and carcinogenic potential (CP) were used to evaluate carcinogenic and mutagenic risk contribution. The mean indoor and outdoor PM2.5 concentrations were 38.7μg/m3 and 93.3 μg/m3 respectively, which exceeded WHO Air quality guideline (2004). The mean ∑15PAH concentrations in indoor and outdoor air samples were 267.1 ng/m3 and 843.4 ng/m3, respectively. There was a good correlation of PM2.5 and PAHs between indoors outdoors. Indoor MEQå7PAHs was 41.4 ng/m3, whilst outdoor MEQå7PAHs was 137.3 ng/m3. The mean level of indoor TEQå15PAH was 64.6 ng/m3, whereas the outdoor TEQå15PAH was208.8 ng/m3. Dibenz(a,h)anthracene (DahA) and benzo(a)pyrene (BaP) are the most contributors on the carcinogenicity and mutagenity of PAHs indoors and outdoors
Chemical composition and antimicrobial activity of the essential oil from leaves of Magnolia coriacea (Hung T. Chang & B. L. Chen) figlar growing in Vietnam
Full text linkLeaf essential oil of Magnolia coriacea (Hung T. Chang B. L. Chen) Figlar growing wild in the Bat Dai Son Nature Reserve, Ha Giang Province, Viet Nam was obtained by hydrodistillation and its chemical composition was analyzed using GC/MS. In total, 45 compounds were detected in the essential oil, accounting for 87.1% of the oil, in which 37 compounds were identified accounting for 66.9%. Bicyclogermacrene (12.6%) and spathulenol (17.0%) were the main components of the leaf essential oil of M. coriacea. Antimicrobial activity of the essential oil sample was tested against three microorganism strains using an agar disk diffusion method. The results show that the inhibitory zone diameters ranged from 8.5 to 20.5 mm. Median inhibitory concentration (IC50) and minimum inhibitory concentration (MIC) of the essential oil was determined using microdilution broth susceptibility assay against seven test microorganism strains. Bacillus subtilis had the highest sensitivity with IC50 and MIC values of 185.9 and 512 µg/mL, respectively.
New records of the genus Miconchus (Mononchida, Anatonchidae) for Vietnam nematode fauna
Full text linkTwo species of the genus Miconchus, viz. M. dahousiensis and M. baeticus, were recorded for the first time in Vietnam. The two collected species from Tuyen Quang, Ha Giang and Bac Can Provinces were redescribed and illustrated.
Multi-correlation between nematode communities and environmental variables in mangrove-shrimp ponds, Ca Mau Province, Southern Vietnam
Full text linkMulti-correlation between bio-indices of nematode communities and ecological parameters in mangrove-shrimp farming ponds in Tam Giang commune, Nam Can District, Ca Mau Province, Vietnam were investigated. In which, diversities of nematode communities and several environmental variables in eight ponds were considered to process. Our findings underlined the high diversity of nematode communities in mangrove-shrimp farming ponds compared to other mangrove habitats. Nematode diversities provided more oppotunity in natural food for shrimp. Single correlation analyses showed that the species richness index correlated significantly to three variables (salinity, total organic carbon, and total nitrogen), the Margalef diversity index correlated to two variables (salinity, total organic carbon), and the expected number of species for 50 individuals index correlated with one variable (salinity). Results of multi-correlation analyses between the nematode bio-indices and the environmental variables were completely different from those of single-correlation analyses. In multi-correlation analyses, the species richness and the Margalef diversity index correlated to two variables (salinity, total organic carbon), Pielou’s evenness index and Hill indices correlated with dissolved oxygen, also the Hurlbert index correlated to total organic carbon. Hence, it is necessary to pay attention to the impact of complex interactions between the multi-environmental variables and nematode communities. This research aims to explain the differences between single- and multi-correlation for evaluation of the effects of environmental factors on nematodes as well as aquatic organisms.