Vol. 16 No. 4 (2018)

The aim of this studywasto identify potyviruses from lettuce leaf samplesshowing virus-like symptom collected from sixprovinces in theRed River Delta. The leafsamples were inoculated onto indicator plants such as Chenopodium quinoa, C. amaranticolorand Nicotiana benthamianafor examining the presence of the viruses. Furthermore, total RNAs wereextracted from the leafsamples and amplified by RT-PCR using universal primer pairs, CI-For and CI-Rev, for the detection of potyvirus. After inoculation,indicator plants showed yellow spot and systemic infection on C. quinoa, C. amaranticolorand mosaic on N. benthamiana,indicatingthat lettuce the leaves were infected withvirus. RT-PCR amplificationof about 0.7 kb revealedthat the leaf samples were infected by genus potyvirus. Sequencingof RT-PCR products showed 99.0% nucleotide identiy of C terminus of the cylindrical inclusion (CI)withLettuce mosaic virus(LMV). LMV infectsGomphrena globose, Datura metel, Pisum sativumand Solanum lycopersicum in the pathogenicity test.This is the first report onLMV in Vietnam.

Plant identification is the basis for taxonomic classification and effective use of plant germplasm. In the present study, theplantspecies,Paris vietnamensis(Takht.) H.Li was characterized in terms of morphological characteristics. In addition, DNA barcodes based on ITS and psbA-trnH regions were analyzed. In comparison with other species of Parisgenus, P. vietnamensiswas characterized by several distinctive features such as: free portion of anther connective cylindrical; inner tepals longer than outer ones; ovary 4 - 7 deeply ribbed, horizontal cross section star-shaped, style inconspicuous,andseeds with red aril. DNA barcoding analyses provided support for the use of the ITS region as an efficient DNA marker for molecular identification of this species within ParisL. Genus.

This experiment was conducted to evaluate the combining ability of erect leaf maize inbred lines for grain yield and leaf angle using tester x line analysis. Twelve erect leaf maize inbred lines and three testers, T1, T2 and T3, were crossed in a tester x line scheme in 2017 spring season. Growth and development of thirty-six testcrosses, the check GS9989, and fifteen parental lines were evaluated in a randomized complete block design in 2017 winter season. Results showed that the lines had leaf angle in the range from 26.5o to 30.8o; whle leaf angle of testcrosses varied from 24.1o to 43.1o. Three lines, D3, D6 and D9 showed high GCA values and can be used in hybrid breeding program. D9 line had significant GCA and high variance for SCA, thus, it is a valuable source in maize breeding. The T3 tester had higher GCA effect for leaf angle and yield and T2 tester had higher effect for leaf angle. Five testcrosses, T3xD3 (72.8 tons per ha); T3xD6 (72,2 tons per ha); T2xD9 (70.2 tons per ha); T3xD9 (83.1 tons per ha) and T2xD10 (77.1 tons per ha) with erect leaf and yield being higher or equal to the check GS9989, are promising for further testing and large scale demonstration for releasing new hybrids suitable for high density cultivation.

Leydig cell tumor is one of the most common testicular tumors in dogs. The objective of the present study was to examine the clinicopathologic and immunohistochemical features of canine Leydig cell tumor. Testicular tumors (Leydig cells) were found in the testicles of six dogs in veterinary clinics in Hanoi. Clinical symptoms included swelling, hyperpigmentation on the scrotal skin and/or hematuria, perineal hernia, and squatting to urinate. The tumors were macroscopically small, yellow to brown, soft and sharply demarcated with hemorrhage or cysts on cross-section. Microscopically, all cases show a similar histological appearance, being composed of round to polygonal cells with (or without) fine vacuoles in pale, abundant eosinophilic cytoplasm, a small and round eccentric nucleus, and infrequent mitotic figures. Neoplastic cells, in solid sheets (100%), angiomatoid (66.67%) or pseudo-adenomatous (50%) pattern, frequently contained testicular degeneration, lipid accumulation, hemorrhage and cystic structure. Immunohistochemically, tumor cells in all cases were positive for vimentin, inhibin-, melan-A and E-cadherin, but negative for neuron-specific enolase (NSE). These results help in the education and diagnosis of canine Leydig cell tumor and support future studies of tumor in animals.

The Vietnamese native chickens have low egg production so they is difficult to breeding andtheir population is declining.Polymorphisms (24-bp Insertion-Deletetion và C2402T) of Prolactin geneis usually considered as candidate genes in the genetic analysis for the improved performance traits in poultry. The study was conducted to determine two SNPs polymorphisms (24-bp Insertion-Deletetion and C2402T) of Prolactin gene in two Vietnamese native breeds Ri and Mia chicken.For genotyping of individual was identified by PCR and PCR-RFLP methods. The results showed that the individual’s genotype was identified in two Riand Mia chicken breed. For 24-bp Insertion-Deletetion polymorphism, the II genotype in Ri chicken and Mia chicken present at low frequencies, (0.07) whereas for DD genotypes in Ri and Mia chickens occur at high frequencies, 0.68 and 0.82, respectively. For C2402T polymorphism, the study shown that two breeds (Ri and Mia) had the highest TT genotypes, respectively 0.64 and 0.84; The CC genotype in both Ri and Mia chickens appeared at low frequencies of 0.08 and 0.07, respectively.

The objective of the study wasto calculate drought basedon meteorological data (rainfall, temperature and humidity) at meteorological stations in the areafrom 1984 to 2016. Inthis study, we used the drought index - K (based on the water balance) to assess the level of the drought with4 degrees:none, less, moderate, and extreme drought. The distribution of rainfall (R) and evapotranspiration (E0) were interpolated and extrapolated by using GIS to build drought zone maps. Results showed that Binh Thuan is adroughtprone areabecause of very few rain in the dry season. Besides, the drought was fluctuating with time and space. In recent years,extended severe dryness occurred,concentrating in the Eastern Coast of theprovince in dry seasons.

This study was conducted to assess the impact of coal mining on landscape, environment and land use in Ha Long City. The methods used for collecting data collection were secondary materials, field survey, household interview, map editing and data statistics, and soil and water sampling and analysis. Results showed that coal mining seriously affected land use. In the 2010 -2017 period, the area of coal mining has increased by 740.13 hectares while forest area decreased by 520.44 hectares and land cover decreased 15.12%. Soil quality also degraded due tpcoal mining. The contentsof heavy metals (As, Pb Cu, Zn, and Cd) of coal waste dump sites weremuch higher than these of agricultural cultivated sites according to QCVN 03-MT:2015/MONREstandards. Particularly As was 5.4 to 9.45 times higher than QCVN 03-MT:2015/MONREstandard. Coal mining increased contents of Fe, Mn, TSS (total suspended solids) and COD and decreased pH in both surface water and in ground water systems. Moreover, coal mining activities resulted in increased landslides, landfill, and landform change, which accelerate natural disaster risks and landscape degradation in tourist areas in Ha Long city and in Ha Long Bay UNESCO’s World Heritage.

This study aimed to assess the efficiency of some land use types after conversion from rice land in Nam Dinh province. Surveys were conducted in three districts of Hai Hau, Nam Truc and Y Yen. Results showed that’s the converion of paddy land to other forms such as medicinal plants, specialized vegetables, flowers and ornamental plants brought about the highest economic value (especial flowers and ornamental plants with the highest value of VND 523.94 million/ha, followed by aquaculture of VND 475.9 million/ha, integrated farm with VND 429.87 million/ha and medicinal plants 234.69 million VND/ha). Land coversion has improved social benefits, created more jobs for local workers, increased income for farmers and made positive changes to the enviroment in production. Conversion of paddy land to other forms of land uses significantly contributed to the land use efficiency and promoted the mechanization of local agricultural production.

The purposesof this study wereto selectandidentify species of lactic acid bacteria (LAB) capable of producing high extracellular cellulase and to determine some cultural conditions affectingcellulase production of selected strains. Fortystrains producing extracellular cellulasewere selected from 120LAB strains isolated from some traditional fermented foods. Of40 strains producing extracellular cellulase, 10 strains produced cellulase withhigh enzyme activities with diameter of substrate hydrolyzing zone reachingfrom 11 to 15 mm. DP4.8 strainwithhighest cellulase productivitywas further investigated onthe effect of some culture conditions such as carboxymethyl cellulose (CMC) concentration, cultural temperature, cultural time on producing cellulase. Results showed that CMC concentration of 1.0%, culture temperature at 37oC, and culture time (36h) were the best conditionsfor producing cellulase.In addition, DP4.8 strain was analysedbypheSgenesequencingandcomparedwiththe known sequence database in EMBL and BCCM/LMG collection of Ghent University, Belgium. This strain was identified to be Lactobacillus rossiaes.

The objective of this research was to study the effect of lycopene extracted from tomato waste on quality attributes such as pH, H2S, NH3, peroxide value, and total aerobic microorganisms of raw pork meat during preservation. The raw lean meat was sprayed with the lycopene solution of 0.1% and 0.3 % at 5 ml per 100g meat, then stored at 5±10C. The results showed that the lycopene extracted from tomato waste prolongedthe shelf life of lean meat during cold storage for 6 and 9 days at concentration of 0.1% and 0.3%,respectively. The supplement of lycopene to pork meat not only prolongs its shelf life but also provides human diet ofantioxidant sources.

The study was carried out on perilla seeds (containing 30.09%oil) harvested from plants cultivated in Dong Dư (Gia Lam-Ha Noi)to select the most suitable processing methods andto optimize the processing techniques of seed oil extraction. Two- time dynamic extraction was selected as the most suitable method to extract oil from perilla seeds. The main processing factors were examined in order to enhance the oil extraction yield and oil quality. The optimised processing conditions were identified. The seeds were ground into powder with particle size of 0.2 mm. The ground materials were then extracted 2 times by n-hexan at 60 oC and at a solid/liquid ratio of 1/6 in 5 hours for the first extraction and 1/5 in 4 hours for the second one. The obtained perilla seed oil had good nutritional quality with high levels of essential polyunsaturated fattyacids, especially omega-3 which accounted for 58.3% of total fattyacids.

Calculation and design for a 3-roller sheet bending machine for small production operationswere based on theoretical studies and real manufacturing practices. Dimension parameters of the machine were calculated based on materials used in manufacturing process and machinery parts. The bending machine can manufacture machinery parts with different diameters and heights by using some types of steel with thickness from 1 to 4 mm, length from 400 to 2000 mm and width from 50 to 800 mm. Based on design drawing, a 3-roller sheet bending machine was manufactured and used for manufacturing machinery parts.

During the last three decades,the agricultural policies, especially land policy,have been renovated and enabledimpressive development of Vietnam’sagriculture. However, agriculture sector is still unsustainable. One of the core causes of this situation is the slow process of land accumulation and concentration. This paper discusses concepts, viewpoints and modes of land accumulation and concentration. Based on the land accumulation and concentration facts during the last years, the paper proposes some recommendationstorenovate agricultural land policies for commodity oriented agricultural development.