Vol. 10 No. 4 (2012)

The ladybird beetle, Scymnus hoffmanni, is a potential predator of aphids. The life cycle and adult fecundity were examined at laboratory. Life cycle of S. hoffmanni was 18.54 days for larvae reared on maize aphids, shorter than those reared on soybean aphids (19,92 days). Oviposition period lasted 19 days. Number of eggs deposited by female were 179.72 eggs. The number of maize aphids killed by S. hoffmanni 4th instar larvae and adult per day were 8.34 and 12.84, respectively. Maize aphids were preferred by S. hoffmanni in a prey preference test. Results obtained from this study provide basis for research on the utilization as predator in the biological control of aphids species.

A total of 31 upland rice varieties with low yield but good drought tolerance potential was used to examine their culturabilty in vitro(callus induction and plant regeneration) and to preliminarily establish genetic transformation protocol. Of 31 rice varieties, 25 have good callus formation with a induction rate of more than 50% and four of them have very high callus formation rate, varying from 76.3% (Khau tram họm variety) to 85% (Khau cong ton variety). The MS medium supplement with 1.5-2mg/l 2,4D seemed to be optimal for callus induction while supplement with 2mg/l BAP, 0.5mg/l kinetin and 0.1mg/l casein was optimal for plant regeneration. Analysis of variance (ANOVA) showed that the callus forming potency and plant regeneration capacity of these rice accessions were influenced by culture media and genetic background (genotype). The gene OsDREB2ACAwas successfully tranformed using Agrobacterium tumefaciens into Khau tram hom variety.

The effects of different doses of gamma rays (0, 15, 18, 21 kR) on mutagenic induction in soybean (Glycine max (L.) Merill) cv ĐVN6, ĐT12 and ĐT20 were investigated. The sensitivity response of soybean to gamma radiation was determined based on seed germination, plant survival and growth reduction in the M1 generation. The mutation changes were observed on the morphological and agronomic characters and yield components, including leaf color and shape, maturity, plant height, branching habit, number of branches per plant, pods/plant, 1000 seed weight and yield/plant in the M2, M3 and M4 generations. In general, the reduction of phenotypic expression in M1 generation is proportional with the dose of gamma irradiation. Although cultivars responded slightly different, the critical dose for inducing mutation was established at 21 kR. In M2 generation high proportion of chlorophyll and agro-morphological mutations were observed, indicative of effectiveness of mutagenic treatment. With regard to quantitative traits, both negative and positive shifts in mean values as well as increased phenotypic variation were recorded in M2, M3 and M4 generation as a result of mutagenic treatment. Moderate to high broad-sense heritabilities in the M3 generation were found for plant height, number of branches, number of pods per plant and seed weight, but rather low for grain yield per plant, suggesting possibility for improvement through selection of yield components. A total of 15 M4-lines possessing agronomic and yield contributing traits similar to or better than the parents were selected and they offer good scope for improvement of soybean.

An experiment was carried out to compare two-line hybrid rice combinationsin Winter-Spring and Summer-Autum season inEakar, Krong Ana and Buon Ma Thuot City of Daklak province. The resultsshowedthat thehybrids have short growing duration,ranging from 92-112 days in Winter-Spring season and 89-114 days in Summer-Autum season. They have from 12.0 to 13.5 leaves per main stemandplant height ranging from 75.0 to 100.0 cm. They have good resistance to diseases and insects, such as brown plant hopper, baterial leaf blightandleaf blight. They have yield ranging from 7.8-9.1 tons/hectare in Winter-Spring season and 6.3-8,4 tons/hectare in Summer-Autum season. Based on yield and quality three hybrid combinations, viz.TH3-3, TH3-5, and TH7-5 were selected for development of two-line hybrid rice in Daklak province.

The study was conducted toestablishaneffective protocol for rapid propagation of jewel orchid,Anoectochilus setaceusBlume. The most suitable organs for explants were shoots and stem nodes.They were sterilized and cultivated in many different mediums (MS, Knud, Knudson). Then, they will be transferred to the best medium added BA, Kinetine,αNAAfor 4 weeks.The optimal medium for shoot proliferation was Knud* 0,5mg/l BAP + 0,3mg/l kinetin + 0,3mg/l NAA + 20g/l sucrose + 0,5g/l charcoal + 7g agar/l.The multiple shoot induction was 6,55 shoots/sample. The shoots had stem length from 3 to 4 centimeters were used to plant in the medium to induced root in vitro. The rate of roots induce in vitro were 100% and the number of roots per samples is 4,21 roots/samples. The medium was added 1mg/l αNAAis the best medium for inducing root in vitro.

The report presents research results of the development stages of scaly giant clam’s (Tridacna squamosa Lamarck, 1819) gonad in 8 Vietnam islands from 2010 to 2011. The scaly giant clam samples were collected in coral reef (from March to July) and from the divers in Nha Trang Bay and adjacent areas (in months). Histological method was employed to analyze the development stages of gonad. The research results showed that scaly giant clam is a hermaphroditic species. The individuals with the shell length under 18-20cm exhibit maleness character while in individuals with the shell length above 18-20cm the gonad differentiate into spermary and ovary. The development of scaly giant clam’s gonad experiences 6 stages (from stage 0 to stage V). Among them, stage III, the largest size are in the eggs and sperms. The egg cells are round or elliptic in shape and arranged with each other in the ovaries. Diameter of the eggs is measured at 90-110μm. The spermary contains a large quantity of mature sperms; the sperm head size is about 3μm. The research results are useful for identifying each stage of the development of scaly giant clam’s gonad and breeding season through the level of the gonad maturity.

The classification of the species in genus Botia(Botinae, Cobitidae, Cypriniformes)currently have been changed. The genus BotiaGray, 1831, is separated into 4 genera: BotiaGray, 1831;SyncrossusBlyth, 1860;SinibotiaFang, 1936andYasuhikotakaNalbant 2002.In Vietnamrecorded 9 species of genus Botiawere recorded but no updated documentsconcerning the above-mentionedgenusclassification. Relying on thesescientific basesof the separation genus of Botia, established key identification genus, description characterisations genus of the loach, established key identification of species and description species of loach in Vietnam.The authors have definitedsciencetific name of loach inVietnam. Itshowed that only remaining 8 species but in 3 other genus. Genus YasuhikotakaNalbant, 2002 including 4 species and genus SyncrossusBlyth, 1860 including 2 species distributing in the Southern Vietnam and Highlands. Genus SinibotiaFang, 1936 have2 species distributing in highlands provinces of Northen Vietnam. This article providingupdate documents for convinience in research and and uniform scientific names of loach species.

The study was conducted in 33 castrated male pigs of Yorkshirex Landrace crossbredto analyze the association of polymorphisms of myogenin (MyoG) and Leukemia-Inhibitory-Factor (LIF)genes with some economic traits for growth and carcass performance. The genotypes of MyoG were significantly associated with carcass percent, in which pigs with heterozygous genotype AB (76.32±1.30) was superior to the homozygous genotypesBB (72.77±1.30) and AA (69.46±2.91) (P=0.05). In addition, in LIF locus, the association between genotypes and carcass length also showed significant difference (P<0.05), with the highest carcass length occurring in pigs withhomologous genotype BB (78.00±2.84). Therefore, it is suggested that allele “B” in both candidate genes could be used as a SNP-marker to improve carcass performance in pigs.

Diarrhea is a major cause of economic loss in cattle and pig farming. The aim of this study was epidemiological survey of prevalence and molecular typing of C. perfringens isolates associated with diarrhea in cattle and pigs. The study was carried out from 2007 to 2010 in Hanoi and surrounding areas (including Bac Ninh and Vinh Phuc provinces). The biochemical properties of isolated C. perfringens were tested. The results showed that: all isolates of C. perfringens had biochemical properties as described before. PCR typing of isolates was carried out by multiplex PCR. C. perfringens isolated from fecal samples of diarrheic cattle were type A (57.34%), type D (41.33%) and type C (1.33%); whereas all C. perfringens isolated from fecal samples of healthy cattle, diarrheic and healthy pigs were type A. The prevalence of cpe and cpb2 varied with isolated genotypes. There was a significant association between cpb2 positive C. perfringens isolates and diarrhea in pigs. Of the 304 isolates from pigs with diarrhea examined, 138 (45.39%) were positive for the cpb2 gene and 52 (17.11%) were positive for the cpe and cpb2 genes, whereas none of the isolates from healthy pigs were positive for the cpb2 gene.

Nespora caninumis a parasite which was first detected in Norwegian dogs and has been known as an important abortive cause of cattle. A high abortion rateup to 44% occurs in N. caninumpositive pregnant cows.. Besides, consequence of infection could be culling of the aborted dams, reductionof milk production and weight gain, and increase of veterinary, diagnosisand replacement purchase costs. Various methods have been studied to prevent and control N. caninuminfection in cattle. However, there are no highly effectiveapproaches available in terms ofboth epidemiological and economic aspects so far.

The experiment was carried out to investigate the suitable feed for Chilata ornatareared from fry to fingerling stage in earth ponds. The experimental fish with the mean size of 2- 3cm/fish were reared in earthen ponds at 4 fish/m2 and fed with three types of feed: TAHH (100% commercial pellet with 35 crude protein), HH&CT(50% commercial pellet (50% crude protein) and 50% flesh trash fish) and CT (100% flesh trash fish) for 36 days. The experiment were set up in two replications. The results showed that growth and survival of C. ornate; feed and protein efficiency were not significantly (P> 0.05) affected by the feed sources. Food conversion ratio was significantly (P< 0.05) lower in TAHH treatment than in other treatments. The lowest cost to gain 1kg fish was also observed in TAHH treatment which was significantly (P< 0.05) lower than those in other treatments. Environmental factors such as DO, NH3 and pH were in the safe range for C. ornataculture. It is recommended that commercial pellet (35% crude protein) can used as substitution for fresh trash fish for rearing C. ornatafrom fry to fingerling stage.

The study of Cu, Pb status in agricultural land in Van Lam district, Hung Yen provinceshowed that Cu content in soil varied in a quite great range, from 21.91 to 91.06 ppm soil, Pb content was from 24.25 to 948.77 ppm soil. Agricultural land closed to metal recycle trade villages of Chi Dao commune and industrial zones Pho Noi A and Nhu Quynh was polluted by Cu and Pb (Total Cu content exceed 1.28 to 1.82 times of the limit in QCVN 03.2008 BTNMT; Total Pb content exceed 2.14 to 13.55 times of the limit in QCVN 03.2008 BTNMT. Land in trade villages of Chi Dao commune was severely polluted by Pb. The Pb content in soil exceed 10.03 to 13.55 times of the limit in QCVN 03/2008 BTNMT

The aim of this study was executive the fermentation by microbes to produce Bioethanol from Agricultural wastes after harvesting in order to reuse the wastes in most efficiency, forward to develope the subtainable Agriculture and contribute into environmental protection. The results obtained suggested that two microbescombination were chosen, which suitable for fermentation process including: combination of bacteria and molds with high abilities in organic degradation could use in period of pretreatment and decomposing raw materials and yeasts combination with ability in fermentation of saccharose into ethanol.The test of inoculation and fermentation of Agricultural wastes by microbes combination proved that activities of useful microbes in fermentation lead to increasing nutrients content in remain wastes, especially effect of ethanol production was preeminentin treatment of inoculation in anaerobic condition, at the same time supplying microbes by interrupted way,which suitable with fermentation process, the ethanol content increased 12 - 15 times comparing to control.

The study focuses on Linh Dam New Town in the south-west of Hanoi - the biggest and most diverse new residential area of the city with many projects of New Towns. Hanoi expansion to the south-west will relieve the overburdened center and re-configure densities. Accordingly, a series of projects of New Town has grown up with types and sizes and different characteristics to provide new and modern living spaces for residents. Linh Dam New Town was selected for investigation to discern an overview on the development of high-density and diverse new residential area in the south-west of Hanoi. The set of criteria used to analyze the case study included Structural Plan, Uses and Activities, Public Space, Trafic, and Typological Characteristics of Architecture, in order to find out strengths and weaknesses of the project, as an example for other New Towns in the south-west of Hanoi.

At the present, about 53% female rural labors work partime in Hanoi. With a low literacy level, they often choose jobs as family care, selling goods in the streets or in-waiting labor markets. Although working time is rather long (11-13 hours/day) and continuously, their montly income average only ranges from VND 2.34 to 3.8 million. 100% labors selling goods in the streets and in-waiting labor market have to work in unsafe environments; their daily life are rather poor. 22.86% female freelane labors live in boarding houses characterized by poor facilities, insanitation and unsafeness. They always feel lonely and home-sick and lack of leisure time. Both internal factors (literacy levels, ages, health status, marital status, job-orientation) and external factors (living and working environments in cities, home-town customs, working conditions and relating policies) were identified as the determinants affecting to jobs and daily life of female rural labors working part-time in Hanoi. Some policy measures were proposed to be taken to help female rural labors working part-time in Hanoi for better jobs and life.

Foreigndirect investment (FDI) has taken a crucial role in Vietnam’s development processsince the launch of Renovation in 1986. After Vietnam’s accession to the World Trade Organization (WTO), a large amount of FDI capital flowed into country, up to 140 billion USD, due to the openness of country’s economy, more transparent, predictable investment environment, and several national advantages. Wherein, there was a switching of FDI capital from manufacturing sector to service one together with a downward trend in agriculture. Like previous duration, Vietnam’s FDI capital sources came mostly from Asia-Pacific region and European economies (net capital, technology exporters) probably caused by Vietnam’s integration emphasizes in dynamic Asia-Pacific region. Another interesting finding was that, geographical allocation of FDI was characterized by concentration on three main key economic regions: the Red River Delta (surrounding Ha Noi, Hai Phong, and Quang Ninh), the Central region (surrounding Da Nang), and the Southeast of country (surrounding Ho Chi Minh City) owing to better infrastructure, abundance of skillful labor force, and bigger market size. To use/attract FDI capital more effectively and enhance the role of FDI in Vietnam’s development process, some suggestions were also proposed.