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TRADE LIBERALIZATION AND FOREIGN DIRECT INVESTMENT IN VIETNAM: A GRAVITY MODEL USING HAUSMAN - TAYLORESTIMATOR APPROACH

Hoang Chi Cuong , Do Thi Bich Ngoc, Dang Huyen Linh, Bui Thi Phuong Mai

Received: 07-01-2013 / Accepted: 19-02-2013
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.
Effect of Dietary on MatureRate of Female Otter Clam and Survival of Larvae(Lutraria philippinarum)

Vu Van Sang, Tran The Muu

Received: 05-11-2012 / Accepted: 23-02-2013
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).
An Assessment of Tourists' Satisfaction at Sam Son Beach in Thanh Hoa Province

Nguyen Viet Dang , Nguyen Thi Trang

Received: 09-05-2012 / Accepted: 12-06-2012
Sam Son beach in Thanh Hoa province is one of the most beautiful beaches in Vietnam attracting millions of tourists each year. However, the beach is facing several problems such as the average number of days that tourists spent at the beach is decreasing, service quality is not good, etc. A questionnaire of 57 evaluation criteria using Likert scale is used to interview 83 tourists to measure tourists' satisfaction in five main groups of services at Sam Son beach and propose some measures to improve the tourists' satisfaction. Analysis results show that quality of the main groups of services at Sam Son beach is acceptable. Only 27.69% of the inteviewed tourists satisfied with services at the beach with the average satisfaction index of 3.05. The beach did not really satisfy high-income tourists. The availability of the current services is only sufficient to meet the needs of low income tourists and local customers. It is necessary to take measures to improve the tourists' satisfaction such as promoting investment in infrastructure and facilities for tourism development, timely correcting defects in service delivery, enhancing professional qualifications for service staff, etc.
Rapid In-vitroPropagation of Exotic Dragontree (Paulowniafortunei)

Nguyen Thi Lam Hai, Tran Dong Anh, Pham Thi Thu Hang, Dinh Truong Son, Dang Thi Thanh Tam, Nguyen Thanh Hai, Nong Thi Hue, Ninh Thi Thao, Luu Thi Hoa

Received: 14-12-2022 / Accepted: 02-03-2023
Dragon tree (Paulownia fortunei)introduced from Canada is a woodenplantwith high economic value due to its outstanding growth rate, hightimberquality, and tolerance to insect pests and diseases. Because of exoctic origin, rapidpropagation by tissue culture to produce large quantity of planting materials isnecessary and suitable for the development of this species in Vietnam. Explants were collected from three-month-old plants. Theywere treated with 0.1% KMnO4for 30 minutes, then sterilized in 0.5% troclosenesodiumsolution for 20 minutes, followed by0.2% HgCl2for 10 minutes. Finally,the explants were soaked in 100mg/lcefotaxim solution in 10 minutes for innitialculture with survivalrate of 35.7%. The best medium for in vitroshootregenerationwas MS medium supplemented with 0.5 mg/lBAPwith the shoot multiplication rateof 5.43 shoots/explantand averageshoot height of 4.32cm. The best medium for in vitrorooting was ½ MS medium for 3weeks. Growthsubstratefor high survival rate was peatmoss (97.2%)after 3 weeksof acclimatization.
Efficiency of Sex Pheremone Lures to Rice Yellow Stem Borer at Red River Delta

Ho Thi Thu Giang, La Van Hao, Hoang Duc Dat, Bui Thi Thanh, Nguyen Hong Thuy, Nguyen Van Dinh

Received: 16-07-2012 / Accepted: 19-09-2012
Five types of sex pheromone lures: Standard DJ- 2 mg (Z11-16Ald:Z9-16Ald) 3:1 ratio; Combined 1mg DJC - Z11-16Ac: Z13-18Ac 1:10 ratio and 1mg Z9-16ald: Z11-16Ald with 1:3 ratiol; DJZ1 - Z9-16:Ald (25 µg), Z11-16:Ald (75 µg) and Z9-18:Ald (12.5 µg); DJZ2- Z9-16:Ald (250 µg), Z11-16:Ald (750 µg) and Z9-18:Ald (125 µg) and DL - Z11-16:Ald: Z9-16:Ald with 2:1 ratio were tested in bottle trap design experiments conducted at Hanoi and Hai Phong. The experiment was arranged in a randomized complete block design with 5 replications. The distance between traps was 30m. The results showed that the average number of adult males caught in a trap per night was highest at the combined lure (DJC), followed by the standard lure (DJ) and the least was DJZ1 and DJZ2. Integrated effect of 4 components of the combined lure (DJC) showed the highest effect. Additional components (Z9-18L: Ald) compared with standard (DJ) has reduced the number of of adult males.
Resources of Seaweed around Nam Du Archipelago, Kien Giang Province, Vietnam

Do Anh Duy, Tran Van Huong, Do Van Khuong, Dam Duc Tien

Received: 07-09-2021 / Accepted: 21-01-2022
The study was conducted to assess the status of seaweed resources distributing around Nam Du archipelago, Kien Hai district, Kien Giang province. In four trips in three years from 2017 to 2019, using the field survey method of deep diving with SCUBA, combined with sampling, the research team identified 96 seaweed species belonging to 51 genera, 35 families, 20 orders of 4 seaweed phyla. Our results also recorded 1 seaweed species (Tubinaria decurrens) belonging to the list of endangered, precious and rare species that needs priority protection in the Vietnam Red Book (2007). The average coverage at the survey stations was 17.0 ± 3.8% and average biomass weas 1,946 ± 217 g/m2. The fresh seaweed resources were estimated at 1,751 ± 195 tons on 90 hectares around the archipelago. Some seaweed genera were predominant on the island, such as Turbinaria, Sargassum, Padina, Palisada etc. The results provide an essential scientific basis for the development orientation and management of seaweed resources in the coastal region around Nam Du archipelago, Kien Giang province.
Age and Size Effects on Spawning Performance of pathegen-free Broodstock of White Leg Shrimp (Litopenaeus vannamei)

Vu Van Sang, Vu Van In, Tran The Muu

Received: 11-07-2013 / Accepted: 08-11-2013
Experiments on the effects of broodstock size at 35-39g; 40-44g; 45-49g; 50-55g and 60g (experiment 1) and age ranging from 7; 8; 9; 10 and 11 months old (experiment 2) to reproductive performance of white leg shrimp (Litopenaeus vannamei) broodstocks free of pathogen were conducted in in-door composite tanks of 14m2(for broodstock intensive rearing) and 1m3(for spawning and larval rearing) under biosecurity conditionattemperature of 28-30oC, and salinity of 28-30‰. Shrimpswere fed 4 times per day with blood worm (50%) and fresh squid (50%).Water was renewed 100% daily. For breedinginduction, eye-stalk ablation was applied to the female shrimpsafter 30 days intensive rearing. Female shrimps of 45g or bigger showed significantly better reproductive performance than smaller ones (P<0.05), reaching mature rate of 89.0%, mating and spawning rate of 86.0%, fecundityof 175,200 eggs/dam/spawn, and nauplii production per spawn of 88,700 nauplii. On the other hand, shrimpsat age of 8 -12 months have considerably higher spawning performancecompared to age group of 7 months (P<0.05) with mature rate of 86.7%, mating and spawning rate of 84.1%, fecundity of 207,400 eggs/dam/spawn, production of nauplii per spawn of 127,500 nauplii.
In VitroPropagation of Yellow-Flesh Taro (Colocasia Esculenta(L.) Schott) Collected in Thanh Son District, Phu Tho Province

Nguyen Thi Lam Hai, Pham Thi Thu Hang, Dinh Truong Son, Dang Thi Thanh Tam, Nguyen Thanh Hai, Do Thi Kim Ngoc, Nguyen Thi Thanh Thuy

Received: 10-06-2020 / Accepted: 22-09-2020
The yellow-fleshtaro belongs to the group of taro (Colocasia esculenta(L.)Schott)andis the native taro of Thanh Son district, Phu Tho province with high nutritional and economic value. The yellow-flesh variety is now being degenerated due to clonal propagation for many generations,therefore this study aims to rejuvenate this taro variety usingplanttissue culture. The mature tubers were used as a material to initiate in vitroculture.The in vitroshoots formed after the initial culturewerecut and culturedin MS medium supplemented with the different plant growth hormones for rapid shoot multiplication. The shoots were subcultured to MS medium supplemented with growth regulators belonging to the auxin group for rooting. The results showed that the optimal medium for rapid shootmultiplication was MSmedium supplemented with1.0mg/L BAP which would multiply 9.65 shoots/sample. The rooting medium for in vitroshoots was MS mediumsupplementedwith0.3 mg/L α-NAA with a rooting rate of 100%. The in vitroplants weretransferred to the greenhouse and grown in soil substrate and coconut fiber in 1: 1 ratio, the survival rate was 90%, the plantlets showed vigorous growth and produced new leaves after 2 weeks of acclimatization.
The Association of Insulin and Insulin Like Growth Factor Binding Protein 2 Gene Polymorphismswith Body Weight in Lien Minh Chicken

Tran Thi Binh Nguyen, Nguyen Thi Thanh Tra, Do Thi Thu Nguyet, Nguyen Huu Duc, Le Cong Toan, Nguyen Thi Dieu Thuy, Nguyen Manh Linh, Hoang Thi Yen, Vu Cong Quy, Vu Duc Quy, Pham Thu Giang

Received: 10-06-2020 / Accepted: 19-08-2020
Lien Minh chicken is an indigenous breed with several favorable propertiesand associated with the economic development of the people in the Lien Minh village, Cat HaiDistrict, Hai PhongCity. Chicken Insulin (INS) and Insulin-like growth factor binding protein 2 (IGFBP2) are physiological candidate genes involved in the growth traits. This study aimed to investigate the association of single nucleotide polymorphism (SNP) of INS and IGFBP2genes concerned with bodyweight inLien Minhchicken.The indexes for 100 Lien Minh chickens were observed individually about their body weights from 01 day to 20 weeks age.Blood samples were used for DNA extraction and then genotyping by PCR-RFLP method. Two SNPs of INSandIGFBP2genes were analyzed. Allele frequencies ofINSand IGFBP2were: A (0.65), G (0.35) and A (0.46), T (0.54), respectively. Genotype GG INSshowed the highest values of mean body weight at 14, 16weeks of age for hen, 18 weeks of age for cock (P <0.05), and genotype AAof IGFBP2 (IGFBP2)wasalsoshown thehighest values of mean body weight at 20 weeks of age. These results suggested that the beneficial alleles/genotypes could be used to support the improvement of the egg production capacity in the breeding of Lien Minh chicken.
Effects of Organic Additives on Shoot Elongation of Dendrobium lituiflorum Lindl.

Dang Thi Thanh Tam, Tran Thi Thu Huong, Nguyen Thi Lam Hai, Nguyen Thanh Hai, Dinh Truong Son

Received: 10-06-2020 / Accepted: 12-12-2020
This study aimed to investigate the effects of adding several organic additives on the growth of the Dendrobium lituiflorum shoots. In vitro shoots of 1cm length were separated from protocorm-like body and cultured on the MS medium supplement with different organic additives such as homogenate of potato, germinated green bean, yam bean or banana pulp or coconut water with the concentrations of 50 mg/l or 50 ml/l, respectively. The results indicated that adding potato or yam bean homogenate promoted shoot elongation. Combination of 50 g/l potato homogenate with 10 g/l green bean homogenate or 50 g/l yam bean homogenate with 0.5 g/l active charcoal resulted in longer shoots. This is the first report on the effects of yam bean homogenate on orchid shoot development. The findings could be applied on a large scale of producing in vitro plantlets of Dendrobium lituiflorum.
Greenhouse Gas Emission Reduction from Pig Production in the Context Restructuring Livestock Sector in Hai Duong Province

Tran Van Quan, Tran Dinh Thao, Nguyen Tho Quang Anh

Received: 25-11-2019 / Accepted: 10-02-2020
Hai Duong is one of the leading agricultural development provinces, especially the livestock sector. The pig herdsof the province areannually about 600 thousands ofheads. The objective of the study wasto assess the current status of livestock production, pollution andeconomic efficiency of thereductions in the greenhouse gas emissions.The study was conducted based on the secondary data and surveyeddata of 120 household farms, combined with in-depth interviews withtheofficials and technical experts in Hai Duong province. The results showedthatfarming householdsare currently using three measures to reduce greenhouse gas emissions in pig production, including biogas, enzyme probiotics and composting.In which, the composting method showedthe highest profit-cost ratio with 2.98 times,followingby 1.94times in biogas and the least is 1.21 timesby using probiotic enzymes,
Detection of Virus-Like Particles (VLPs)inOtter Clam Spat (Lutraria philippinarumReeve, 1854)Colected from Hatchery

Dang Thi Lua, Phan Thi Van, Nguyen Thanh Thuy

Received: 25-09-2018 / Accepted: 29-01-2019
Swollen siphon disease has been considered as a serious threat to otter clam farming in Vietnam. Virus-like particles (VLPs) were identified asthe main causative agent of the disease, however, the transmission pathway and the pathogenesis of the disease has not been clarified yet. In this study, by using electron microscopy analysis, some host species such as otter clam spat and venerid clam (Tapes dorsatus) were selected to screen for the presence of VLPs and VLPs were further analyzed and described their size, structure and location in the host cells. The studies showed that VLPs were found in otter clam spat that were sampled from the hatchery. This finding indicated that the otter clam spat is one of the causes of spead of the wollen siphon disease in otter clam. VLPs have rod-like shape with the size ranging from 70-90 nm x 600-1.000 nm. They consist of outer shell, outer membrance, inner membrance, coreand are located in the cytoplasm of the host cells. Thesestudiesare playsed as scientific basis for developing strategies for classification of VLPs and control, prevetion and treatment of swollen siphon disease in otter clam.
Evaluation of 24-bp Insertion-Deletion and C2402T Polymorphisms of the Prolactin Gene in Two Vietnamese Native Chickens: Riand Mia Chicken

Nguyen Hoang Thinh, Nguyen Thi Chau Giang

Received: 01-03-2018 / Accepted: 20-06-2018
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.
Current Status of Seed-borne Mycoflora on Rice Seed OM6976 and OM4218 and Efficacy of Plant Extracts on Fusarium spp. Isolated from Rice Seed

Le Thanh Toan, Vo Thi Tuyet Nhung, Ho Minh Thuyen

Received: 24-11-2017 / Accepted: 25-12-2017
In current rice production, discoloration of grain is one of the most important diseases, leading to reduction in yield and deterioration in grain quality. The research was carried out to obtain current status of rice cultivation and seed-borne mycoflora of two rice varieties OM6976 and OM4218 at Chau Phu district, An Giang province. In addition, in vitro activity of plant extracts was tested against Fusarium sp. that are common seed-borne infection among rice seed mycoflora. Results of interview from 60 households showed that grain discoloration, blast and bacterial leaf blight were the important rice diseases. Examination on seed-borne mycoflora from 6,000 rice grains indicated that there were 12 kinds of fungi on both rice varieties, namely Fusarium sp., Curvularia sp., Pinatubo oryzae, Trichoconis padwickii, Tilletia barclayana, Nigrospora sp., Acremonium sp., Penicilium sp., Aspergillus sp., Chaetomium globosus, Bipolaris oryzae and Phoma sorghina. Among them, Fusarium sp. accounted for high percentage (29.5%) in variety OM6976. The rate of Curvularia sp. was high at approximately 24.6% in variety OM4218. Eupatorium leaf extracts at concentration of 2, 4 and 8% highly inhibited the growth of Fusarium sp.
Study on Micropropagation of Strawberry “Smia”

Nong Thi Hue, Pham Thi Thu Hang, Tuong Thi Thanh Huyen, Nguyen Thi Thuy Linh, Nguyen Thi Lam Hai, Nguyen Thanh Hai

Received: 20-09-2017 / Accepted: 31-01-2018
Strawberry “SmiA” is a potential variety with outstanding features such as heart- shaped fruit, dainty little red berries with an ambrosial flavor of strawberry, rose, pineapple and honey. This study was carried out to establish in vitro micropropagationprotocol from in vitro germinated plants. The best shoot proliferation (7.8 shoots/explant) was obtained from explants grown on MS medium supplemented with 0.4 mg/l BA after 5 weeks. In vitro shoots were rooted on semi-solid MS medium with 0.25 mg/l α-NAA, maximum rooting rate (93.33%) with 12.36 roots/shoot and average length (1.49 cm) of roots was achieved after 4 weeks. The plantlets were successfully acclimated and well developed in soil substrate with a high survival rate. NPK fertilizer combined with Atonik solution was most appropriate for growth and development of in vitro SmiA plantlets with the average height of 19.13 cm after 1 month. Flowering was observed after 20 - 25 days of flower-bud formation, and masses of dainty, sweet tasting berries were produced after 30 - 35 days.
Properties of Soil on Hai Hau District, Namdinh Province

PhamAnh Tuan, Nguyen Ich Tan, Nguyen Quang Hoc

Received: 06-05-2013 / Accepted: 14-08-2013
Based on analysis of soil samples Hai Hau soils can be classified into 3 groups with 9 soil types, alluvial soil being the lagest area with 8,976.61 ha, occupying 39.20% of the natural area, followed by saline soil group with 4,8725.16 ha, accounting for 21.28% of the natural area. Sandy soil has the smallest area with 422.89 ha, occupying 1.85% of the natural area. The physical and chemical properties of all soil types are suitable for many types of annual crops. Soils have a good structure with soil thickness, porosity and soil texture from sandy loam to clay. The chemical properties of soils fluctuate strongly, especially soil salinity and depending on type of soil, but in general, soils react neutral to weak alkaline, with high basic saturation. Soils have medium to high phosphorus and potassium conccentration and moderate fertility .sandy soil group, however, has low fertility.
Effect of Different Bottom Substrates on Survival Rate and Growth ofJuvenileSea Cucumber (Holothuria scabra) Cultured in Tanks

Nguyen Thi Ngoc Anh

Received: 01-01-2016 / Accepted: 17-07-2016
A study was performed to evaluate the effect of different bottom substrates on survival rate and growth of juvenile sea cucumber (Holothuria scabra) cultured in tanks. Experiment consisted of 4 treatments namely sandy substrate, muddy substrate, sand+mud sustrate mix with 1:1ratio,and brick substrate. Each treatment was repeated three times.Juvenile sea cucumberswithmean initial weight and length of 3.51± 0.14 g and 4.35± 0.51 cm, respectively,were kept in the 250- L tank and provided with slightly continuous aeration at salinity of 30 ppt, and stocking density of30 individuals/m2. After 75 days of culture, survival rate of sea cucumber in sandy, muddy and sand+mud substrates was in the range of 94.4- 100%, and not significantlydifferent(p> 0.05). Particularly, the sea cucumber in the brick treatment experiencedgradual mortalitywith time and complete death at day 62 of culture. The highest specific growth rate and daily growth rate in termsof length and weight of H. scabrain the sandy treatment was observed, and significantly different (p< 0.05) from other substrates. The results suggest that sandy substrate was most suitable while the brick wasnot appropriate for juvenile of sea cucumber H. scabra. Moreover, H. scabracould live and develop on the sand+mud and muddy substrates in tank conditions.
Evaluation of Houssehold’s Satisfaction of Service Quality of Electricity Supply in Hung Yen City Area, Hung Yen Province

Ngo The Tuyen, Ninh Xuan Trung, Ngo Thi Thuan

Received: 22-02-2017 / Accepted: 12-04-2017
Purpose of this research is estimating consumer satisfaction with the quality of electricity service; identifying and analyzing factors which have an influence on household satisfaction with services of Hung Yen Power Company in Hung Yen province. The information is collected by surveying 110 households using electricity (based on 27 standards in 6 groups of service quality, including service attitude; electricity price; receiving feedbacks; providing information to consumers; payment of electricity and time of delivering to consumers. Research methods are: Cronbach’s alpha, Exploratory factor analysis (EFA) with Likert - type scale and regression model to identify, select and analyze levels of satisfaction as well as factors which impact on customer satisfaction with the quality of electricity service of Hung Yen Power Company in Hung Yen province. The research findings are: the level of household satisfaction with the service quality of Hung Yen Power Company in Hung Yen province which bases on research indicators is normal; there is a positive correlation between household satisfaction and group of factors such as time of delivering to consumers, receiving feedbacks, service attitude and providing information to consumers.
Composition of Parasitic Fungi on Coffee Root Mealybugs and Cicadas in DakLak Province

Dao Thi Lan Hoa, Tran Thi Thuong, Mai Thi Hanh, Nguyen Van Phuong, Nguyen Van Nam, Do Thi Kieu An, Tran Thi Hue

Received: 10-05-2015 / Accepted: 22-06-2016
A study was conducted to isolate parasitic fungi on mealybugs and cicadas attacking coffee roots, making materials available for research and selection of entomopathogenic fungi with high activity to produce biopesticides for controlling mealybugs and cicadas damaging on coffee roots. In 2013, 421 samples of coffee root-ìnfested mealybugs and cicadas parasitized by fungi were collected from coffee plantations in Dak Lak province. A toatl of 156 isolates of entomopathogenic fungi belogning to 4 genera were isolated, including Beauveria, Cordyceps, Metarhizium and Paecilomyces. Based on morphological identification, 18 samples were selected for DNA sequencing and 7 species were genetically identified, i.e. Beauveria bassiana, Cordyceps bassiana, Cordyceps cicadae, Cordyceps takaomontana, Metarhizium cylindrosporae, Paecilomyces lilacinus and Paecilomyces hepiali. These are new species parasitized on coffee root mealybugs and cicadas and are identified for the first time in Viet Nam by DNA sequencing.
Effects of Plant Growth Regulators and Micronutrients on In vitroGrowth and Flowering in Roses

Nguyen Thi Thuy, Ngo Thi Viet, Nguyen Thi Phuong Thao, Nguyen Thi Thuy Linh, Ninh Thi Thao, Nguyen Thi Lam Hai, Nguyen Thanh Hai

Received: 18-05-2015 / Accepted: 02-12-2015
An in vitro flowering system has been considered as a convenient tool not only to study flowering mechanism but also to produce commercial in vitro flowers. This study evaluated effect of plant growth regulators (BA and TDZ), AgNO3 and CoCl2 on growth and in vitro flowering of three rose varieties (HV, HD, HT). The results showed that all tested compounds had different effects on plant growth but only TDZ and AgNO3 were able to induce flowering. On MS medium containing 0.2 mg/l TDZ, only HV variety was induced flowering with the rate of 72.2%, while on medium supplemented 30 M AgNO3, after 21-25 days, all three varieties HT, HV and HD were induced flowering with the rates of 30%, 40% and 50%, respectively; the flowers lasted as long as 14-16 days.
In VitroPropagation and FlowerInductionof Rosa sericeaLindl.

Nguyen Thi Phuong Thao, Dang Quang Bich, Nguyen Thi Thuy, Nguyen Thi Thuy Linh, Pham Thi Thu Hang, Dang Thi Thanh Tam, Ninh Thi Thao, Nguyen Thi Lam Hai, Nguyen Thanh Hai

Received: 24-03-2015 / Accepted: 04-06-2015
This study was conducted to determine optimal media for in vitro propagation and flowering of rose (Rosa sericea Lindl) collected in Phu Tho province, Viet Nam. 99.78% of rose explants formed shoots on MS medium supplemented with 2.0 mg/l BA and 0.05 mg/l α-NAA. The optimal medium for micropropation was MS medium containing 1.5 mg/l BA. 100 % of the shoots produced roots on ¼ MS. The study showed that AgNO3 and CoCl2 had positive impacts on in vitro flowering of the rose plantlets. On medium supplemented with 30 M AgNO3 or 30 M CoCl2, flowering rates were 50 % and 20 %, respectively. On medium containing 30 M AgNO3, flower longevity last 14 days after anthesis whereas on medium including 30 M CoCl2, flowers only last 7-8 days.
ĐadạngsinhhọctỉnhHảiDương: HiệntrạngvàTháchthức

Nguyen Thanh Lam, Cao Truong Son, Nguyen Thi Huong Giang

Received: 20-02-2014 / Accepted: 15-07-2014
Biodiversity study was carried in three major ecosystems, aquatic, terrestrial and agricultural ecosystems to evaluate current status and challenges of biodiversity conservation in Hai Duong province in 2013. In this study, 1,033 species of plants and 881 species of animals in the terrestrial ecosystem; 314 species of animals and plants in the aquatic ecosystem have been identified. Rare and precious species have been identified including 39 species in the Vietnam Red Book, 28 species in Government Decree No 32/2006, and 88 species in the Red list of threatened animals of IUCN 2011. The results revealed that biodiversity resource in Hai Duong is unevenly distributed, the mountainous area being richer in biodiversity than the delta areas. The study also identified 8 hotspots for biodiversity conservation. Finally, major challenges to biodiversity loss were identified such as habitat loss, pollution, invasive species, over-exploitation and climate change, weaknesses in state management and lack of public awareness.
Evaluation on Economic Losses of Arising Wastes from Food Processing Handicraft Villages in the Red River Delta Region, Vietnam

Tran Van The, Nguyen Tuan Son, Nguyen Nghia Bien

Received: 20-11-2013 / Accepted: 03-01-2014
Despite thesocio-economic benefit, productionactivities in food processing handicraft villages have causedpressing problems on environmentand economic losses for farmers. The study results indicatedthat economic losses due to wastes from food processing operationsin handicraft villages varied from VND 2.9to 5.6 billion per annum;, whereineconomic losses from cassava starch and cana vermicilli processing villages were higher than other food processing handicraft villages. Health cost and change in agricultural productivity accounted for 57.53% and 24.58%, respectively,of the total economic losses. To reduce economic losses due to wastes arising from food processing in handicraft villagesand to ensure sustainable development, the study suggestedthat government should support to replan waste water collection system, solid waste tratementtechnology; issue and enforcecraft village-specificenvironmentalstandards; increase awareness and promote benefit and responsibility sharing among households and community, and strengthen environmental management activities and sanctionmeasures..
Growth and Survival Rate of SPF Vannamei Broodstock Candidate (Litopenaeus vannamei) Cultured in Indoor System at Different Stocking Density on Cat Ba Islands, Hai Phong

Vu Van Sang, Le Van Nhan, Nguyen Phuong Toan, Nguyen Huu Ninh, Tran The Muu, Vu Van In

Received: 03-08-2012 / Accepted: 25-09-2012
Litopenaeus vannamei) cultured in biosecurity system. Three groups of experimental shrimp (initial weigh 20.1±1.9 g/male and 21.4±2.2 g/female) were stocked at densityof10, 20 and 30 heads/m3in4m3indoor tank system. Each treatment was run in triplicate and fed with about 4% shrimp weight daily with pellet diets of CP 7704S and 7704P (38% crude protein), feeding four times a day. The water temperature ranged from 20.0 - 28.5oC and salinity ranged from 20-28‰. Water was renewed 80% volume weekly. The highest growth rate in weight was recorded in broodstock candidates cultured at 10 heads/m3(1.03 g/week/male; 1.11 g/week/female), followedby 20 heads/m3(0.89 g/week/male; 0.98g/week/female) and the least for 30 heads/m3(0.53 g/week/male; 0.62 g/week/female). Similarly, survival rate of shrimp at 10 heads/m3(71.7 ± 2.7%) ranked highest and the lowest rate for the 30 heads/m3 (60.1 ± 2.8%; P<0.05). Nevertheless, there is no significant difference in the survival rate between shrimp cultured at 10 heads/m3(71.7% ± 2.7%) and 20 heads/m3(71.5 ±3.0%; P>0.05). Size variation (CV%) and FCR recorded on 10 heads/m3 (CV%: 6.34 ± 1.12%; FCR: 2.78 ± 0.5) and 20 heads/m3(CV%: 6.68 ± 1.20%; FCR: 2.86 ± 0.3) were found remarkably lower than that for 30 heads/m3(CV%: 10.56 ±2.24%; FCR: 3.42 ± 0.8; P<0.05). The percentage ofshrimp harvested thatmet the criteria of broodstock was 67.1 ±2.6% and 66.7 ± 3.2% for the 10 and 20 heads/m3, respectively, whereasonly 23.1 ± 5.4% for the 30 heads/m3. All shrimp sample tissues were found negative for WSSV, YHV, TSV, MBVandIHHNV.
The Impact of 2008 Global Financial and Economic Crisis on Foreign Trade of Vietnam

Hoang Chi Cuong, Bui Thi Thanh Nhan

Received: 27-06-2013 / Accepted: 22-08-2013
The global financial and economic crisis, which was triggered by the Lehman Brothers shock in September 2008, has had enormous negative impacts on the global economy and Vietnam. In this paper, some gravity models were constructed using the Hausman–Taylor (1981) estimator, Fixed-effects (FE), Random-effects (RE) estimations, and applied to recent panel data that includes 18 of Vietnam’s major trade partners during the period from 1995 to 2011. This purpose was to examine the possible impacts of the 2008 global financial and economic crisis on the export and import of Vietnam. The authors found evidence broadly consistent with the prediction that the crisis strongly reduced the country’s import. By contrast, there was no evidence that demonstrated convincingly that this crisis decreased the country’s export. In addition, the authors modeled and found the reciprocal relationship between the export and import of Vietnam.

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