Vol. 11 No. 1 (2013)

In this study, we used DNA markers (5 RAPD markersand 5 SSR markers) to screen genetic diversity in 60 samples of taro(Colocasia esculenta)that collected. Total 67 alleleswere amplified by RAPD markers, in that has 47 polymorphic alleles. 20 alleleswere amplified by SSRmarkersand 9 alleles were polymorphic. From the electrophoresis PCR products of these two directives, 60 taro accessions were grouped into 12 clusters with similarity coefficients of 0.8 by NTSYSpc 2.1 software. The information found in this study may be used for taro conservation and breeding programs.

The study was carried out to improve in vitro culture of the fungus Sclerotium rolfsii and primary selection of tomato (Lycopersicon esculentum Mill.) resistant cell lines using culture filtrate (CF). Results have identified that culture of Sclerotium rolfsii on PDB liquid medium for seven days was optimum for culture filtrate harvest. The culture filtrate contains not only oxalic acid  but also cellulolytic and pectinolytic enzymes. The toxicity of CF was tested on inhibition of germination of tomato seeds. The process selected tomato cell lines in medium supplemented CF at different concentrations (from 5% to 30% from final volume of media) showed that the concentration of CF ratio proportional share mortality of callus and inversely proportional to generate callus induction rate. Concentration CF is 30% of all the research just does not have the ability to generate callus induction and lethal form. The total phenol content of the callus increased in the selection process. In the second cycle selection with a 25% of CF the stability of the total phenol content of the preliminary conclusion that the callus adapt selective factor.

The pot experiment was carried out in the greenhouse to estimate the effect of different fertilizer levels on photosynthetic and physiological characters at active tillering, flowering and early ripen stage of barnyard grass (Echinocloa crus-galli (L.) Beauv) and the rice cultivar Khang dan 18 in both summer and autumn cropping seasons in 2012. Seeds of each species were sown in distinct pots containing 6 kg dry soil per pot. When rice and grass had 2 leaves, the plant was kept in single pot. There were three nitrogen levels, no nitrogen (N0), 0.1grN (N1), 0.12 grN (N2) with the same base of percentage N: P2O5 : K2O: 1: 0.5: 0.5 per one kg dry soil. The result showed that photosynthetic rate and dry matter accumulation rate of barnyard grass were higher than those of rice at all growth stages in both seasons, although stomatal conductance, transpiration rate and SPAD of rice were higher than those of barnyard grass. As increasing fertilizer, the photosynthetic rate, dry matter accumulation rate and nitrogen content in leaves were also increased in both rice and barnyard grass.

A study was carried out from December 2011 to August 2012 to evaluate reproductive performance of nucleus herd of stress negative Piétrain (Piétrain) and Duroc pigs raised at the experimental farm of Hanoi University of Agriculture. A total of 35 gilts, including 21 Piétrain (11 with halothane genotype CC and 10 with CT) and 14 Duroc CC gilts were monitored for their reproductive performance. Piétrain boars (3 CC and 5 CT) were mated to Piétrain and Duroc gilts to produce Piétrain purebred and crossbred Piétrain x Duroc pigs. Results showed that genotype of the boar and the sow affected body weight and litter weight at birth and at weaning (P<0.05). Total number of pigs born, number born alive, number alive to weaning, individual bodyweight at birth, individual bodyweight at weaning, litter weight at birth, litter weight at weaning, survival rate at birth, survival rate to weaning were 9.91, 9.26, 8.11 piglets, 1.4, 6.4, 12.97, 51.96kg, 94.32 and 88.55%, respectively. Body weight and litter weight at birth and at weaning of piglets from Piétrain CC boars were higher than those of piglets from Piétrain CT boars (P<0.05). Reproductive performance was highest for Duroc CC sows, followed by Piétrain CC and lowest for Piétrain CT sows (P<0.05). Reproductive performance of the nucleus herd could be improved by using Piétrain CC boars mated to Piétrain CC sows and Duroc CC sows.

Sorption isotherm curve of freeze dried (FD) product was investigated at 20oC, 30oC, and 40oC. Experimental data obtained were verified by eight mathematical models including BET, Bradley, GAB, Halsey, Henderson, Kühn, Mizrahi, and Oswin. Eight models agreed well with experimental data (R2= 0.9374-1,0000) when water activity (Aw) varied from 0.12 to 0.43. However, when Aw is extended ranging from 0.12 to 0.93, only four models named as GAB, Kühn, Halsey and Oswin still show a good agreement with the experimental data. These models can be used in predicting water absorption of FD salmon product at 20oC, 30oC, and 40oC withacorrelation coefficient (R2) ranged from 0.9776-0.9917, 0.9867-0.9991, 0.9821-0.9920 and 0.9464-0.9995, respectively. Errors between experimental and calculated data from the four models were 5.1%, 4.9%, 8.7% and 9.4%, respectively. Water monolayer value is determined at approximately 5%.

Possibility of using rice bran as raw material for common carp feed was evaluated throughthe digestibility value and its incorporation level in diet. The apparent digestibility coefficients (ADC) of rice bran was measured by indirect method using chromic oxide Cr2O3 as inert marker, feces were collected by sedimentation. The chemical composition of rice bran was 8.41% protein and 13.51% lipid. The digestibility of dry matter, protein and lipid of rice bran were high, reachingvalues​​of97.86%, 87.45% and80.21%, respectively. Digestibilityof mineralsinrice branfor commoncarpvery high, reaching87.16%. Comparedwiththeprevious studiesonthedigestibilityoftherawmaterialsforcarp, rice branhasa relatively highdigestibilitywhich can beexplainedbythe different digestibility measure method. Evaluationthe effects ofdifferentricebranincorporation level ongrowth performance was carried out on common carp of size50g/fishwith3diets which weresupplemented35%, 40% and45% of rice bran. The growth performanceoffish fed 35% rice bran diet was significantly better than that of fish fed 40% and 45% rice bran diets. There was no significant difference between growth performace of fish used40% and45% rice bran diets. Rice bran can be incorporated in common carp diet at the suitable level of 35%. Thedaily growth weight gain was 2.23 g/fish/day and feed conversion ratio was 1.87 for common carp fed diet contenning 35% rice bran.

The experiments were carried out to evaluate the effects of temperature and salinity on embryonic development of the Tiger grouper (Epinephelus futcoguttatus)and to determine the optimal temperature and salinity for incubation of Tiger grouper eggs. The fertilized egg of Tiger grouper was incubated in a series of 1L-glass beakers at a density of 100 eggs/L and divided two separated trials. The first experiment was conducted at five temperature levels of 23ºC, 26ºC, 29ºC, 32ºC, 35ºC, each treatment was run in triplicate. The second experiment was implemented at different salinity of 23‰, 26‰, 29‰, 32‰, 35‰. The study results clearly show that the highest hatching rate (89.6 ± 3.2%) and the lowest deformity rate (6.3 ± 0.4%) were obtained in the treatment which were incubated at 29oC compared to the others (P<0.05). The second experiment demonstrated that the salinity of 32 -35‰ are suitable for incubation of tiger grouper egg as the highest hatching rate of 83.4 -85.6% and the lowest deformity rate of 1.79 -1.85% were obtained (P<0.05). In conclusion, among the treatments, the temperature of 29ºC and salinity of 32 and 35‰ are the best conditions for Tiger grouper eggs incubation.

The present study conducted on three different breeds of Tau Vang (n=237), Noi (n=34) and commercial Cobb 500 chickens (n=23) aimed at evaluating single nucleotide polymorphims in IGFBP2 (Insulin-like growth factor binding protein 2) using PCR-RFLP method. Three poplymorphisms at positions g.639G>A (exon 2), g.1023C>T (intron 2) and g.738G>A (exon 3) were detected based on restriction enzymes Bsh1236I, Eco72I and Alw21I, respectively. Genotypic and allelic frequencies at these polymorphisms, which were also identified in previous studies, have effects on economic traits in various chicken populations and follow Hardy-Weinberg equilibrium. These can be considered as important evidences for developing further studies for IGFBP2 polymorphic association with growth, meat yield and meat quality traits in Tau Vang chicken.

Dietary study onintensive rearing female otter clam(Lutraria philippinarum)stocked at a density of 30 pieces/m2 in 1m3 composite tank using Schizochytrium and fresh algae complex (Chlorella, Isochrysis, Chaetoceros) showed significantly higher percentage of mature and spawning in female otter clam fed on Schizochytrium (92,86 ± 1,50%) than that fed on fresh algae (74,06 ± 2,50%; P<0,05); however, there was no considerable difference in absolute fecundity, fertilization rate and rate of transformation to Trochophore larvae between the two treatments.Other experiment on survival rate of larvae otter clam fed on mix of Schizochytrium and Spirulina while the other fed on fresh algae complex (Isochrysis galbana, Chroomonas salina) from 4 to 21 days in 2m3 composite tank demonstrated no significant distinction in survival rate between the two experiments with survival of 21,6 ± 5,6% and 20,4 ± 3,5% respectively (P>0,05).

The study focused on analyzingthesituationofland recoveryfortheconstructionofindustrialzones; influenceofagriculturalland recoverytoeconomic growthandeconomicrestructuring, laborrestructuring, the employment and income ofthehouseholdswhich are recovered land , thechallengesofland recoveryinthe development process. Research results show thatfrom2000 -2010, VanLamdistrictagriculturalland recoveryof14,260playshouseholds; totalarearecoveryis928.52ha, ofwhichagricultural landis736.50ha. Positiveeconomic structuralshiftin the direction ofincreasingtheproportionofindustryandconstruction(from 31.00% in 2000to74.99% in2010) andreducedtheproportionofagriculture(57.50% in2000toreduceto12.65% in2010). The average incomeper man rosefrom3.82millionin2000to27.2millionin 2010. Creatingmore new jobs, attractingaround25,000employeesto work intheindustrialzones, etc.However, thelossofagriculturallandhas madepartoffarmersunemployed, raisinganumberothersocialactivities, directlyaffectson their lives. Specifically, households with agricultural land recovery rate (> 70%) have high rates of job change (94.17%), thus their income, spiritual and cultural life also increase in comparison with the past. On the actual results of the investigation, there are still some households with income unchanged, a number of households whose income is less than before, focusing mainly on households with land recovery rate is low (<30 %), the mentality of the people is afraid to change careers, which is the main reason, so they try to hang on the remaining agricultural land.

Foreign direct investment (FDI) plays a crucial role in the process of development for Vietnam. Over the two decades of Renovation, a large number of FDI capital flowed into the country, especially after joining the WTO in 2007, an amount reaching up to approximately USD 229,913.7 million. A gravity model constructed using the Hausman – Taylor (1981) estimator was applied to 1995 to 2011 panel data that included 18 of Vietnam’s major country partners and provided by Vietnam’s authorities and international organizations. The purpose was to reexamine the possible effect of trade liberalization under the WTO regime and various FTAs on FDI flows. The estimates were consistent in line with the prediction that the WTO exerted great impact on FDI flows to Vietnam. By contrast, there is no evidence that demonstrates convincingly that the various FTAs in which Vietnam has signed/joined recently, increased FDI capital into the country. The paper also proposes recommendations for attracting FDI and using FDI capital more effectively.

Clam aquaculture has been practiced in Nam Thinh commune, Tien Hai district since 1989, but exhibited instabilllity recently, especially in terms of economic aspect. The study aimed to analyze the economic performance of clam aquaculture and propose recommendations to develop clam aquaculture in a more sustainable manner. A household survey of 48 clam farmers and key informant interviews were conducted in 2012. Gross margin analysis and comparative statistics with t-test and F - test were employed to analyze data. Results show that given the existing resources, technical level, and farmers’ expertise, farms specializing in meat clam aquaculture, and/or operating at medium size, have highest economic performance. A number of problems relating to resources, seed, techniques, knowledge, water conditions, and social conflicts were addressed and recommendations to develop clam aquaculture were proposed accordingly.

This paper concentrated on the implementation of state regulations on pesticide trade management in the Red river delta. Based on secondary and primary data collected by different techniques and statistical description, the research showed that pesticide trade inspection has been frequently carried out. However, some shortcomings were happened in pesticide trade management such as low inspecting frequencies, inadequate punishment for someones breaking the regulations, few pesticide trade inspectors, and so on. Empirical data witnessed that a number of pesticide traders have not implemented regulations on work permit, permissible petsticide list, shop location, safe equipments, and pesticide arrangement. In order to deal with these limitations, Government needs to issue policies on knowledge upgrading for both traders and inspectors and on level of pushnisment for regulation breakers.

The objective of this paper was to understand the existing situation of people’s willingness to pay for health insurance at Hatinh city and then, to propose some measures to improve the situation. The research results were based on a survey of 200 households conducted in middle 2012 at 4 study sites of Hatinh city. The survey showed that a number of the people willing to pay for health insurance exhibits an increasing trend, but it shares a small proportion among total people holding the health insurance card. The rate of people visiting to the health care station using insurance card is high, but they still have to face with some troubles, such as long wait and medical staff’s unenthusiasm. Based on the interviewees’ opinion, the research proposes some measures to attract the people’ participation in the voluntary health insurance. They are: (1) promoting the dissimination of voluntary health insurance law; (2) enhancing the quality of health care services, (3) improving the staff’s attitude and ethics toward patients, and (4) reducing the administative procedures in the service of health care via the voluntary health insurance.   

This paper reviews the previous studies related to value chain in Vietnam as well as in the world and discuses views of value chain and value chain analysis for aqua-culture sector including concepts, components, and actors of the value chain. This paper also discusses the models and methods that have been used to analyze performance and efficiency of the value chain. The results pointed out that value chain analysis in aqua-culture should consider four primary issue contents: mapping, analyzing performance, management and improving value chain. In particular, analyzing performance and efficiency of the value chain need to evaluate four areas: performance and efficiency, flexibility, responsiveness and product quality.

This paper reviews the previous studies related value chain in Vietnam as well as in the world; discusing on views of value chain and value chain analysis for aqua-culture sector including concepts, conponents, actors of the value chain. This paper discusses also on models and methods have been used to analyze performance and efficiency of the value chain. The value chain analysis in aqua-culture refers to four stages: mapping, analyzing performance, management and improving value chain. In particular, the content analyzing performance and efficiency of the value chain need to evaluate four areas: performanceand efficiency, flexibility, responsiveness and product quality.

Foreigndirect investment (FDI) plays a crucial role in the process of development for Vietnam. Over the two decades of Renovation, a large number of FDI capital flowed into the country, especially after joining the WTO in 2007, an amount reaching up to approximatelyUSD 229,913.7 million. Agravity model constructed using the Hausman – Taylor(1981) estimatorwasapplied to 1995 to 2011panel data that included18 of Vietnam’s major country partnersandprovided by Vietnam’s authorities and international organizations. Thepurposewasto reexamine the possible effect of trade liberalization under the WTO regime and various FTAs on FDI flows. The estimates wereconsistent in line with the prediction that the WTO exerted great impact onFDI flows to Vietnam. By contrast, there is no evidence that demonstrates convincingly that the various FTAs in which Vietnamhas signed/joined recently, increased FDI capital into the country. The paper also proposes recommendations for attracting FDI and using FDI capital more effectively.