Vol. 12 No. 1 (2014)

The new two-line hybrid rice variety TH8-3 (T7S-8/R3) has been recognizedastesting variety by Ministry of Agriculture and Rural Developmentin2010because it combines early maturity, high yield (6.0-8.0 tons/hectare), good lodging resistance and high grain quality. The yield of F1seed production is notyethigh becausethe parental linesare notcompletelypure and instable in terms of critical sterility temperature. Four successiveexperiments were conducted in growth chamber to screen/select female lines that havecritical sterility inducing temperature ≤ 240C,concurrently maintainheterosis of T7S-8/R3hybrid combination. Suitable planting dates and technical measures for F1seed production were also identified. These results can serve as basis to establish protocol for female line multiplication and procedure for hybrid seed production.

Twoexotic rapeseed varieties, Agamax from Germany, Hyola 432 from Australia and a local rapeseedvarietywere evaluated on field where rice was grownprevious season in Dongvan Karst Plateau during 2012-2013. The resultsindicated thattwo exotic rapeseed varieties were adapted to the local weather and soil conditions and gavehigh seed yield per hectare basis (1.820-1900kg/ha) and good seed quality. Theaverage oil content of Agamax and Hyola 432 attained43.6% and 41.3%, respectively. These varietiescan be adopted to integrate into winter cropping structure in Hagiang province.

This study was conducted to estimate heritability of growth traits andlean meat percentage of stress negative Piétrain pigs raised in Dong Hiep livestock farm, Hai Phong province and animal farm of Hanoi University of Agriculture. Sample sizes were 2093, 1380, 895, 494, 338 and 470 for body weight at birth, weaning,60 days, 7.5 months, average daily gain (ADG) and lean meat percentage respectively. Two softwares (Harvey andMTDFREML) were used to estimatethe heritability for each trait. Results showed that stress negative Piétrain pig had a high lean meat percentage(64.12%), however ADG was low (489.54 g per day) due to selection programme and small population. Heritabilitis of body weight at birth, weaning, 60 days, 7.5 months of age, ADG and lean meat percentage were 0.13, 0.12, 0.25, 0.23, 0.31 and 0.19 respectively. These values ​​are consistent with previous studies, except the heritability of lean meat percentage relatively low.

The study was caried out on 100 of broodstock softshell turtle (Tryonyx steinachder) at rate 30 males and 70 females with body weight over3 kg/individual and more two years old in 2012-2013periodat Bo village, Son La city. The results have shown that 1932 eggs were laid and 1207 babiessoftshell turtle were hatched. Soltshell turtle often breed from April to July with 1-2 times per year and 1-22 eggs/time. The number of eggs laid in the first time of second year was higher than that in the first year. However, the hatching rate between two times in the year was not different.

The study was carried out to identify the most suitable stocking density for mouse grouper larvae (Cromileptes altivelis)from fry to fingerling stage. The larvae were reared at the densities of 10,20 and 30 individuals/l. Lower stocking densities, at 10 and 20 individuals/l weremore favorable forspecific growth rate (0.063 and 0.0625%/day), final total length (34.45 and 33.33mm)and survival rate (6.45 and 6.30%)(P<0.05). Results showed that the most appropriate density for rearing the mouse grouper from fry to fingerling stage is 20 individuals/l to optimize the growth, survival rate and economic efficiency.

A study of immigrant plant species in the mangrove forest of Can Gio biosphere reserve was carried out. The survey recorded 137 species, 99 genera, and 38 families belonging to two phyla of vascular plants Polypodiophytaand Magnoliophyta. Among those, 48 new immigrant species were recorded. The immigrant plant resources were also divided into five groups as follows: (1) medicinal plants with 72 species accounting for 52.6% of total species, (2) vegetables with 15 species accounting for 10.9%, (3) ornamental plants with 6 species accounting for 4.4%, (4) household used plants with 4 species accounting for 2.9%, and (5) woodyplants with 4 species accounting for 2.9%. Life form of immigrant plants was divided into five groups including herbs, shrubs, small trees, big trees and lianas.

The study was conducted to assess land useand land cover change in Tien Yen district in the 2000 -2010 period using SPOT images which were acquired in years 2000, 2005 and 2010. The object –oriented approach which was applied in this research includedtwomain steps: firstly, SPOT image was fragmented to vary objects by eCognition software, and, secondly,the segmentation images were classified by Maximum Likelihood approach using training dataset. The samples consisting of nineland usetypeswere collected by handheld GPSdevice. The overall accuracy of 3 image classifications in 2000, 2005, 2010 were 82.74%, 80,97% and 89.33%, respectively. Land useand land cover mapand land use/land cover change map were produced by ArcGIS (version 10.0) software to assess the land use change of the study area. Within 10 yearsperiod, the forest area and mangrove forest increased 3916.91ha and 1720.57ha, respectively. Meanwhile, the swidden and shrublanddecreased 4200.16ha. The increase of forest area in Tien Yen might be explained bybetter awarenessof local people about the benefits and the importance of forest as well as by thethe implementation of national and international projects which support Tien Yen in protecting and developing forest resource.

This research was conducted to evaluatethe current environmental status in Tien Yen district through assessingthe majorfactors and environmental indicators. The results showed thattheair quality isrelatively good; the surface and underground watersarenot contaminated, except few samples showingsigns of TSS and BOD5pollution; industrial wastewastersdo not meetViet Namstandard QCVN; household wastesarenot classified or sorted at the sourceof disposal. There were 75% of total wastes that arecollected and treated. Soil environmental quality was found to be good, but soil erosion was observedin slopping land with slope of 15-25oand above25o, even under in annual crops and forestry plantations near Tien Yen river. Temperature and precipitation in 2000-2012 period differred fromfrom previous period (1980 –1999); (1986 –1999): 8/13 years with highertemperature, 11/13 years with lower total railfall. The land cover was estimated at53%with fairly high species diversity (plants and animals) and diversity of aquatic ecosystems. However,improved management measures should be implemented to prevent forestry burning,cutting downtrees,timber loggingand hunting rare and precious wild animals. Forestry and wild lifeconservation is strongly recommended to increase the land cover and maintain biodiversity.

Rhodomyrtus tomentosaor Rose Myrtleis a wild plant native to Southeast Asia. Itsberry orfruit is sweet, edible and medicinallyused as a folk remedy for various diseases. The fruitcontains high concentration of anthocyanin,a natural polyphenol withpowerful antioxidantactivity. In this study, Sim fruitsharvested from Mang-Den, a highland area in Komtum, were pretreated withpectinase to maximize yield, transmittance (clarify) and anthocyanin in the filtrate. After taste adjustmentwith sugar and citric acid, the juice was pasteurized for preservation. The extraction by pectinase enzymes was optimized using response surface methodology. The results showed that the extraction condition with 0.1% pectinase at 40oC in 60 min wasoptimal for maximum yield of fruit juice (62.93%), clarity (T=38.3%) and amount of anthocyanin (68.52 mg/L). Pasteurizationwith PU858,3 = 9.18 minutes at 85oC for 4 minutes yielded syrup withgood safety and high anthocyanin concentration.

The effects of yeast strains, fermentation temperature and pH on quality of Rhodomyrtus tomentosa wine were examined. At ambient temperature (28±2oC), the fermentation was induced by inoculation with Saccharomyces cerevisiae strains isolated, purified and screened from sugar palm (Borassus flabellifer) and pineapple juice in comparison with commercial yeast (initial populations of yeast raging from 104107 cells/ml). The medium was adjusted before fermentation to five different pH values (3.44.2). The effect of fermentation temperature (20 and 28±2°C) on strain population was also studied. The resulting wines were chemically analyzed. Pure cultures of Saccharomyces cerevisiae isolated from sugar palm significantly yielded in ethanol production higher than other strains in the fermentation at 28±2°C.. Yeast strains performed better at low temperatures with high alcohol yield. At 20±2°C, the fermentation was dominated by the growth of S. cerevisiae in Rhodomyrtus tomentosa juice with maximum ethanol concentrations (13.43%Vol.) The methanol and SO2 concentrations met the Vietnamese Standards (QCVN 6-3 2010/BYT). In addition, the total acid, ester and aldehyde concentration were also low.

Jam is an effective and tasty way of preserving fruit. Most tropical fruits can be processed and preserved in order to reduce post harvest loss in small scale operations. The potential of the nutritious jackfruit (Artocarpus heterophyllus), has remained largely untapped. The study was conducted to investigate the effects of pectin concentration (0.7 to 0.9%) and gum arabic concentration (0.9 to 1.1%); vacuum pressure (450 to 650 mmHg) and holding time (2.5 to 4 minutes) on processing and jackfruit jam quality. Stirred and FOB-type fruit-flavored yogurt were made by adding jackfruit jam at different ratios (5 to 20%). In this work, vacuum technology was proven as adequate to obtain jam with the typical characteristics of water activity, degree Brix and viscosity of jam adding to yogurt. Proximate analysis showed vitamin C in jam 0.45 mg%, pH from 3.9 to 4 and oBrix from 53-54. The sensory evaluation showed that samples submitted to more intense vacuum pressure heating had significantly higher scores in color saturation, brightness, good texture and taste. These indicated that high vacuum pressure treatment prevents jackfruit jam color change and increases the consistency of the jam. In this way, jam was preferred by assessors mainly due to its higher consistency and suitability for adding to yogurt processing. The samples obtained by this procedure were stable during storage. Addition of 15% of Jackfruit jam into stirred yogurt and layered type of yogurt (FOB) provided products with strong aroma, good taste (sour and sweet harmony) and texture without water release.

Stevioside and Rebaudioside A are two major sweeterners of the diterpene Steviol glycosides compounds derived fromStevia (Stevia rebaudiana) leaves. In this study, the levels of Stevioside and Rebaudioside A in the dried leaves of 4 sweet grasses grown in Vietnam weredetermined by high liquid performance chromatography and compared with theKorean sweet grass. Stevioside content in dried leaves of these Steviavarieties ranged from 2.13% to 7.72% and Rebaudioside A (RebA) changed from 2.05% to 9.32%. In particular, the Vietnamese sweet grass S. rebaudianaS77 had the highest STG concentration (11.53%). This is a potential material for production of sweeteners using in food processing technology. In addition, other nutritional components of S. rebaudiana S77 stevia leaf has also been identified, including protein, lipid, carbohydrates and reducing sugars.

In this study, microbial compositions and probiotic properties of 24 commercial probiotic products for human available in 2012 in Hanoi were evaluated. According to the labeled information, all probiotic bacteria in those products belonged to Bacillus, Lactobacillus, Streptococcus and Bifidobacteriumgenera, wherebyL. acidophiluswasmost frequently found with an approximatevalue of 80%. Plate counting method revealed that 13 out of 24 investigated products had lower live cell numbers than those claimedon the labels or in the statustory regulations. In addition, no Bifidobacteriumstrains could beisolated from any products labeled with their names. All 54 isolated strains showedgood adherence to chicken mucus, strong gastric acidic fluid tolerance and high resistance to bile salts. Their antibiotic resistance towards six antibiotics and their antagonistic effect against three common pathogenic bacterial species differed largely with 59.3% of the strains resistant to at least one antibiotic; 5 strains could inhibited at least one pathogenic bacterial species and 9 strains can inhibited all three pathogens.

Effects of soaking conditions (time, temperature and pH of the soaking solution) and germination conditions (aerobic and anaerobic) on the γ-aminobutyric acid (GABA) content of IR 50404 and Jasmine 85 rice varieties were investigated. The rice was kept in water at room temperature (30± 2oC) and moisture content monitored until it reached the optimum absorption. The moisture content saturation attained after 6 h was 27.1 % and 32.7 % for IR 50404 and Jasmine 85, respectively. The pH values of soaking solution of pH 3 for IR 50404 and pH 2 for Jasmine 85 were optimal for production of GABA (70.37mg/100g for IR 50404 and 78.50 for Jasmine 85). Germination under anaerobic condition (10% CO2 concentration) yielded the highest GABA content after 30 hours.

Pesticide risks in terms of hazard and exposure are expected to reduce through community based farmer training. With this regards, a community based training program on pesticide risk reduction (PRR) has been implemented in Vietnam since 2007. With two data sets on 94 pesticide users before and after PRR training in PRR and control communes of Hanoi city and Thai Binh province, this paper shows that: The program has improved farmers’ awareness/knowledge and their behaviors in PRR, and enabled farmers to reduce hazards and exposure. Farmers used pesticides permited for vegetables, used more biopesticides and class III and IV pesticides. On the exposure side, positive impacts were more proper pesticide use techniques; use of more protective equipment and better unused pesticides and sprayer management. As a result, the environmental impact quotients were reduced sharply from 20% to 78%.

The purpose of the study was to understand the current situation and to propose solutions for labor export management issues at labor export enterprises in Hanoi. The results showed that the management activities in those labor export enterprises strictly followed processes and achieved certain efficiency. However, the implementation processes has revealed many shortcomings, such as un-seriously in planning, mass recruitment and training... The main factors affecting these included unqualified staff involving in managing labor export activities and labor export supply and unapproapriate labor export policy. Eight groups of solution proposed included good planning, strengthening marketing and market development activities, improving recruit process, enhancing the quality of vocational education and training, strengthening the overseas labor management, enhancing control, evaluation and adjustment and improving the capacity of the labor managers.

Program Lattice for partially balanced lattice design was written in 1999. In this paper wecompare results analyzedby program Lattice and and found that the results are fit in Lattice Program given by SAS 9.1

In 1995 we wrote programs Dialen2 and Dialen3 to analyze Diallel mating design in single environment using Griffing's method. In this paper we present two programs Dialenk2 and Dialenk3 to analyse multienvironmental Diallel data.