Vol. 14 No. 12 (2016)

Two-line hybrid rice variety LC212 is valuable variety with high yielding potential, short growing duration, widely adaptation to environment but susceptible to Bacterial Leaf Blight (BLB). Backcross breeding method was conducted for transferring Xa7gene to restorer R212 which is male of hybrid rice variety LC212. The plants which have phenotype similar of R212, high resistance to three typical BLB races, carrying homogenous Xa7gene of BC2 and BC3 generation were selected by Pedigree selection. The selected plants were inoculated, similar phenotype was selected and MAS technicque were used to identify Xa7gene. The 25 lines R212BB of BC2F4 and the 8 lines R212BB of BC3F3 were selected. They are using for father step breeding of R212 restorer resistance to BLB as announced improved rice lines LC212.

Rot disease is one of the most serious issues causing considerably significantpostharvest losses on rambutan. With the aim to support in finding outeffective control approaches, an investiagation tittled “ Studies on causal agents of postharvest rot diseases on rambutan in Mekong River Delta was carried out on aspects of including isolation, namingnomenclatureand evaluation of culture conditions.on growing and development of isolated fungi. Results indicated that there were seven fungi were recored as causal agents causing postharvest rot diseases on rambutan,i.e. Lasiodiplodia pseudotheobromae, Phomopsis mali, Lasmenia sp., Gliocephalotrichum cylindrosporum, Pestalotiopsis virgatula voucher, Pestalotiopsis clavisporaand Fusarium verticillioides. Two feature rot symptoms (cloudy and black rots) which have caused by these fungim,could be regconized by nakedeye. All these fungi were greownwell on all three culturemedias of, i.e.PDA (potato dextrose agar), PCA (potato carrot agar) and MEA (malt extract agar) in optimum ranges of temperature 25-30oC and pH 6-8. Among the examinated fungi, Lasiodiplodia pseudotheobromae had a wide growing temperature between15to-35oC and Pestalotiopsis virgatula voucher could be grown at high temperature (45oC).

The knowledge and understanding of genetic variability of common bean (Phaseolus vulgarisL.) germplasm is important for utilization and conservation. The Oobjective of this study was to analyzesis ofgenetic diversity of 60 accessions that collected in Vietnam and from other countries. Results based on mMorphological markers showed that 60 germplasms accessions werearevery diverse and they were dievided into 7 groups with genetic similarity index of 0.17. Using SSR markers to evaluate genetic diversity,Fifteen15SSR markersamong 20 used wereshowed polymorphismcwith total of 69 alleleswith and an average of 4.6 alleles per locus. BM152 marker had highest PIC value (0.73). Four major clusters were grouped for 60 accessions with genetic similarity at 0.69. The,dendrogram showing the genetic relationships was constructed by the unweighted pairedgroup method with arithmetic average (UPGMA) using the software NTSYS-pc 2.01. The results of this study indicatedthat SSR analysis could be successfully used for the estimation of genetic diversity among common bean accessions. The diversity of common beanThatare of the highest usefulnessfor breeding purposes.

Tilapia and common carp are two main cultured species with high annual production annually in freshwater aquaculture in northern Vietnam. , hHowever, there are serious problems caused by bacterial infection. The use of antibiotics is not sufficient to mitigate outbreaks of the diseases due to antibiotic resistance of the causal agentsrate are increasing. Therefore, antimicrobial compounds are potential as a new approach to overcome the challenges of antibiotic resistance. The aim of this study is to isolate and evaluate antibiotic activity of endophytic actinobacteria from May Chang tree (Litsea cubeba) against three pathogenic bacterial species Aeromonas hydrophila GL14, Aeromonas caviaeHD60 và S. agalactiaeHY10. The results showed that 9/32 (28,2%) endophytic actinobacteria isolates could inhibit at least one target pathogenic bacteria. Three isolates MTR711, MTR622 and MTL121 showed the highest antibacterial response with minimium inhibitory concentration (MIC) ranged from 93,3 to 300,0 µl/mL, amongst these the lowest value is for MTR711 and MTR622 without significant difference. When combining three individual actinobacteria mentioned above for fractional inhibitory concentration (FIC) test, the synergistic effect was found for the pair of MTR711-MTR622 against three pathogenic bacteria chosen in this study with ∑FIC ≤0,5. The combination of two actinobacteria MTR711 and MTR622 improved bacterial inhibitory effect at least 4 times compared to individual treatment. The results are motivating enough to conduct further studies on use of endophytic actinobacteria for treating pathogenic bacteria in aquatic animals.

The aim of the present study was to isolate and characterize Escherichia coli(E. coli) from Bau and Domconservation ducks at Dai Xuyen duck breeding and research center. The results showed that ages and breeds of ducks affected isolation rates. The breed differences in composition of serotypes O were observed. Two common serotypes O2 and O78 were not detected in this study. The bacterium bacterialisolates were resistaent to β-lactam, aminoglycoside, and diaminopyrimidine antibiotics. Especially, all of the isolates were resistant to lincomycin. Most of the isolates showed toxicity in Swiss albino mice. To the best of our knowledge, tThis is the first study on E. coliin Bau and Dom duck breeds. The results can be considered as groundwork ofor further studies on E. coliand other microorganisms infecting conservation breeding flocks.

The study was conducted to determine the effects of two housing systems on cortisol concentration of gilts. A total of 20 gilts F1 (Landrace x Yorkshire) gilts with similar body weight and age were randomly allotted into four pens of two group-housing systems (two pens with outdoor yards and the other two without yards, 5 gilts per pen). Saliva cortisol concentration on the days 1, 3, 7, 15, 30, 50, and 80 and plasma cortisol concentration on the days 1, 3, 15, 30,and50 of the gilts after grouping wasere determined by ELISA test and ECLIA (Electrochemiluminescence Immunoassay) using COBAS system, respectively. Results showed that there were no significant differencesin saliva and plasma cortisol concentration of the gilts between the two housing systems (P > 0.05). However, in each housing system, saliva cortisol concentrations on the days of grouping were significantly different (P < 0.05). Cortisol concentration of the gilts in both two housing systems waserehighest on the 1stday after grouping (0.58 µg/ dL in the pens with yard and 0.59 µg/ dL in ones without yard),; they weregradually decreased on the 3rdday (0.48 µg/ dL and 0.46 µg/ dL)and; then theywaserelowest and stable on the following days. Similarly, in each housing system, plasma cortisol concentration taken in the days 1, 3, 15, 30 and 50 after grouping were wassignificantly different from each other (P < 0.05). Plasma cortisol concentration waserehighest in the 1stday after mixing (7.38 µg/ dL in the pens with outdoor yard and 7.17 µg/ dL in the indoor pens), followed by the 3rdday (5.35 µg/ dL and 5.19 µg/ dL), then they were gradually decreased and stable in the following days. A positive correlation between plasma and saliva cortisol concentration was found (withr = 0.73).

The experiment of the effect of temperatureeffecton embryonic development and malformation of pompano (Trachinotus blochii) was carried out at the Northen National Broodstock Center for Marine aquaculture oin Cat Ba, Hai Phong, Vietnam. Five temperature levels of 24oC, 26oC, 28oC, 30oC and 32oC were studied with 3 replicates each. The results showed that,there was a significant differencetbetween five treatments in terms of hatching, deformity and survival rates. The result indicated that the significant highest hatching rate was 47.7% at 24oC. The lowest deformity rate was observed at 24oC (3.3%) but no significant difference was found between 24oC, 26oC and 28oC. The survival rate was higher at 26oC (58,6%) and 28oC (58,2%) after five days of post-hatching than other. The results show that sSuitable temperatures for pompano incubation are ranged from 24oC to 28oC. At 26oC and 28oC, the lowest deformity rate (3,98 - 4,20%) and the highest survival rate (10.48% and 10.69%) after 40 days of post hatching were recorded. From this study, the temperature rangedfrom 26 - 28oC are recommended for pompano rearing.

In this study, we investigated the virulence and pathogenicity of porcine reproductive and respiratory syndrome virus (PRRSV) strain HUA 02 in 8-weeks old PRRSV antibody-negative pigs. Experimental pigs were intranasally inoculated with a dose of TCID50 1,74x106/25 µl (2 ml/pig). After inoculation, the pigs were recorded for clinical signs, virus replication in the blood, and macroscopic and microscopic lesions of some tissues for 21 days post inoculation. The results demonstrated that pigs infected with PRRS HUA 02 virus strain had clinical signs and symptoms of moodiness, fatigue, anorexia, high fever, rapid breathing, dyspnea, skin rash and constipation. Reverse transcription PCR (RT-PCR) results revealed the presence of PRRS HUA 02 virus strain in the blood and nasal swabs of infected pigs at 3 and 5 days post inoculation, respectively. Similarly, the viral load in serum quantified by Realtime PCR showed that the PRRSV loads were recorded in the serum at 3 days post infection, and reached highest level in all infected pigs at 9 days post infection. Macroscopic lesions consistently observed included lung inflammation, congestion, hemorrhage and interstitial pneumonia and kidneys with spotting hemorrhage. In lung the lymph nodes were characterized by swelling and hematoma, and in pericardium with hydropericarditisof pigs infected with PRRS HUA 02 virus strain. The microscopic lesions were observed mainly in lungs with bronchoalveolar inflammation, haemorrhagic lymph nodes, and hemorrhagic glomeruli. The results of our study showed that the PRRSV HUA 02 is capable of causing severe disease in pigs with clinical signs, symptoms, macroscopicand microscopic lesions similar to those of highly-pathogenic PRRS virus strain observed previously in North Vietnam.

Agricultural land use plays the vital role in producing agricultural products and agrciultural commodities. Recently, agricultural land use has changed significantlytowards higherefficiency in An Thi District. The research objective wasto assess the efficiency of sub-land use types to serve asbasisfor the orientation of agricultural land use in the district. The results showedthat there were 5 Land Use Types (LUTs) with 17 sub-LUTs. Some agricultural sub-LUTs were assessed withhigh level of efficiency, such as 2 rice crops + squash, 2 rice crops + tomato, vegetabe crop, fruit tree anh fish. Some agricultural sub-LUTs had high economic efficiency, however, they affected the environment because of the overuse offertilizer and pesticides, such as vegetable crops. Therefore, the results of assessment might serve asa good basis for the orientation of agricultural land use towards efficiency in the future.

This study was carried out to assess biodiversity and environmental services for inplementing payment environmental servicespaymentof Ba Bedistrict, Bac Kanprovince. Keyinformant and household interviewds were two main methods whichwere used to collect information. Results showed that the fauna and flora of Ba Beweare diverseifiedwith many species belonging to the listed in the rRed bBook of Vietnam and of the world. In additon, Ba Behas two main forest ecosystems which distributed in different terrains. As a result, forest of Ba Beproduceddiversified environmental services with high value. However, forest and biodiversity conservation activities of Ba Bedistrict did werenot encouragedpromotebecause the environmental services were exploited and implementedusedineffectively. Hence, in the next time Ba Bedistrict should implement forest and diversity conservations more effectively for maintaning environmental services supply ability of forest ecosystems and promotingeto implement payments for environmental services programs to protect forest resource and improve income for local people.

Residual point in 4 villageThe pesticide store in,Nam Linh commune, Nam Dan district, Nghe An province, which was putting in usedue to the impact of pesticide warehouses was usedfrom during the period 1968 to 1978, has undergone several major disturbancesby war and human activities. At present, the Ppesticidesleftover was mainlycurrently exists –DDT as a consequence is weak due to processof landfill after 1978. The study was conducted to assess the environmental risks of the pesticide residuesalpoint by methods recommended by Vietnam Environment Administration (MONRE) and US EPA.for residual pesticides.The results showed that the area of ​​landunder floorarearemaining warehouse platformof the store contained highDDT(totals) withconcentrations(up to2973 mg/kgsoil), (over hundreds times higher than NTR 54: 2013/MONREstandard). From the original point DDT from the formerly landfill was spread horizontally and vertically transported but not more than 7m in depth. DDT intruded, inroadsinto surface water of ponds in the vicinity (28.175mg/l)and enteredin the near pond), inplants (0.607 mg/kg banana stembody) butthere wasno signs of DDT contamination in the groundwater. The risks of chemicalsexposure of the pesticideslandfill, heavily polluted land, and polluted surface water presentarethe immediate risk of serious impactthat,need to be controlled. Other effects caused by exposure of to polluted sediment, groundwater,and DDT- contaminatedfoodshave lower values ​​Ddare of lower riskTbut negative effects of plant pesticides alsoshould take into considerationbe controlled.

Based oOn the currentavailableequipments, constructing an experimental model combining with equipment system, attachment and automatic submerged arc welding machine to weld Q345B high-strength low-alloy (HSLA) steel with T-letter shapedjointwith,a thickness of plates isof5 mm and 8 mm,respectively. Based on theoretic research into on automatic submerged arc welding technology, experimental welding,using design ofexperimental designsand,data processing were performed to find out parameters of for welding conditions to serve welding process of Q345B steel. Through the initial survey,fix somewith constantparameters and experimental welding with about input parameterintervals and evaluating output parameters, determining the followingparameters of welding conditionswere determined: welding current Ih≈ 440 Aand,welding speed Vh≈ 19,.6 m/h. With parameters of welding conditions that were determined,combining with technological elementsand specific structure, T-letterjoint that was weldinged toensureproducedgood form, dimension and quality.

Crocin belongs to the carotenoids group and is found a lot in Gardenia jasminoides Ellis. It is not only capable of creating color for food, but also has a lot of pharmaceuticalologicaleffects such as improving memory, anti-convulsants, anti-depressants, anti-oxidation, anti-tumor, etc.…The Oobjectives of this study wereisto detemine the crocin extraction methodology from Gardenia jasminoides Ellis and the color durability stability in different conditions. Carotenoid content was determined as described by Kotikova et al., 2011. Crocin content was determined by the Ultraviolet-visible spectroscopy (UV - VIS) at 440 nm wavelength. The results indicated that Gardenia jasminoideswas is apotential material to provide theobtainlarge highcrocin at concentrations,up to 16.04mg/g,for fresh material and 14.63mg/g for driedymaterial. The crocin extraction efficiency reached the peak with ethanol: water solvent (40:60, 50:50, v/v). The best results foroptimalsolvent : raw materials ratioand;fresh and dry materials extracting conditions corresponding were20ml/1g at 40°C in 45 minutes; 25ml/g at 70°C in 60 minutes, respectively. Crocin is stable at the temperatures below 100°C withinduring140 minutes. Besides, crocin is also stable in weak acidand,neutral and alkaline conditions.

Z-score model was well-known as an application for enterprises risk forecasting. Nevertheless, there ithas been few application and useshort of empirical researches using Z- score model in agricultural farms, includung animal production farms. The survey was conducted on a database of 220 poultry production farms in Thai Binh province,using Principal Component Analysis (CPA)fortechnical analysis of five basic groups to caculate Z- score model, with the support of SPSS 20.0.The results of this research: Firstly, buildingTheZ- score model was constructed for the poultry production farmsin Thai Binh province. Besides, this research hasveapplied theismodel on a district in the study to calculate the density and zoning. TheisRresultsshowed that 34% of farms were in the healthy zone, 59% of inthe area is unclear zone,and 7% in the bankruptcy zone. To Rreduceingthe risk of bankruptcy of farms in Thai Binh province, theshould adopt following measuresshould be taken: (1) Raise awarenessraisingabout technical ranchers, markets and risks; (2) Having Self-insurance in the production; (3) Improving Aaccessibilityto agricultural insurance in the same animal stock assurance;and(4) Linkingproduction and consumption linkage to ensuring regulate production.