Vol. 11 No. 2 (2013)

Twenty eight maize (Zea mays L.) inbred lines of different origin were evaluated to select the drought tolerant lines as parents for hybrid maize breeding. These inbred lines was developed from the local open-pollinated cultivars and exotic gerplasm from China and America. To preliminarily identify drought tolerant inbred lines, the lines were grown in plastic pots.containing sterilized fine sand and the following tarits were observed: leaf area per plant, root volume, root length,, plant height, freshand dry root weight, and dry stem weight. The genes or QTLs associated with drought tolerance were analyzed using three specific SSR markers. Data analysis showed that root traits are correlated with yield under drought condition. And cound be considered as primary indicators to determine the drought-tolerance of maize. umc1862 marker was found to be associated with grain yield under stress condition (Ys), nc133 marker associated with the stress tolerance and umc 2359 associated with mean productivity. 28 inbred lines investigated have QTL controlling yield under strees and tolerance. Of these 14 lines that have QTL associated with strees tolerance index. Combining phenotypic evaluation and genetic markers, 5 lines, i.e. TP17, TP12, TP2, TP5 and TP24 are suggested for combining ability testing for future development of hybrid maize varieties with tolerance.

A survey was conducted to evaluate the current situation of Ha Noi University of Agriculture on-campus green system. The study was carried out using questionnaire and the survey and plant inventory were conducted in standardized grids and plots. A total of 2.379 trees were identified which belonged to 70 species, 26 families and 15 orders. The tree groups of cultural and historical value associated with the university’s development are found in main roads and central campus around the Four Lakes. However, there has not been any detailed plan for green landscape in the university so that green spaces include many unsuitable species of plants. Moreover, irregular management results in decreasing tree’s vitality, aesthetic value and use efficiency. In the long run, professional and highly-qualified management team is required to ensure green development on the whole campus and improve public awareness for the maintenance and protection of green spaces.

Effect of substrate, stem cutting length, cutting position and concentration of plant growth regulator on vegetative propagation and and growth of Polyscias fruticosa (L.) Harms was investigated.. The results showed that using the rooting medium mixture of 50% soil + 50% rice husk obtained the highest of shoot height, stem diameter, number of leaves/plant) and number of roots/plant). In addition, uing the main stem with 15 - 20cm length quickly dipped in for 2000 - 3000ppm α -NAA solution for 3 - 5 seconds appeared optimal for growth of Polyscias fruticosa L. stem cutting.

An experiment was conductedonFluvisols Acrisoil duringspring rice from 2011to2012in the the Muong Thanh field,Dien Bien District to compare the quality ricevarieties. The study used three quality rice varieties: HT6, T10 andSH2 and Bac Thom N07 was used as control.Thecultural practices applied tothe experiments, such as seeding rate, crop management, and harvesting was based on the average oflocal farmers. The experiments werearranged in Randomized Complete Block (RCB) and repeated thrice. Growth, yield, and culinary quality were recorded and evaluated. The experimental results showed that HT6 rice variety has highest yield (averageyieldof7.12 tons/ha), higher thanthe control by 11.6%. (P =0.05). HT6 variety brought the highesteconomic efficiency(net profit of VND 37.7million/ha). Qualityanalysis showed that rice variety HT6 has low amylose content, high gel strength, especially, good eating quality with a typical aroma. After cooking rice remains soft, shiny, good adhesive and smooth. HT6 varitey is recommended to the large scale production.

The pot-experiment was carried out in the green house at the Faculty of Agronomy in autumn 2011 and spring season 2012 to evaluate photosynthetic characteristics, dry matter accumulation and plant growth rate of short - growth duration rice genotypes. Two lines, IL 3-4-2-7, IL 19-4-3-8 and control varierty IR24 were used in this study. At active tillering, heading and dough ripening stages, four plants of each line were randomly selected to measure photosynthetic characteristics, such as photosynthetic rate, SPAD value (an indicator of chlorophyll content), leaf area and dry matter biomass in leaves, stems and panicles. The results showed that there was no significant difference in photosynthetic characteristics and dry matter production between IL-lines and IR24. Plant growth rate (PGR) of IL3-4-2-7 and IL 19-4-3-8 from active tillering to heading stages was higher than that from heading to dough ripening stage. In contrary, the PGR of IR24 was the same at two stages. A significant and positive correlation between grain yield and photosynthesis rate at active tillering and heading stages was found in newly selected lines, whereas the significant and positive correlation between grain yield and photosynthesis rate at heading and dough ripening periods was observed for IR24 variery. Grain yield of lines with short growth duration correlated significantly and positively with PGR before heading stage, while grain yield of IR24 correlated significantly and positively with PGR after heading stage.

Drought is a major constraint affecting rice production, especially in rainfed areas of mountainous regions of Vietnam. Development of drought tolerant varieties will improve rainfed rice production. Identification of drought-tolerance of the lines and local cultivars is useful for the development of genetic material and rice breeding for adaptation to rainfed environments. Forty two rice accessions were evaluated for germination and seedling characteristics by treatment of rice seed with KClO3. The plants were planted in PVC pipe to evaluate root length and root growth under well-watered and water-stressed environments. In addition, QTLs associated with root lengthen and root growth were analyzed using SSR markers. We have identified 11 accessiopns (lines and local cultivars) with drought tolerance. Three best drought tolerant accessions, 455 (Khau li on/Q5), 464 (Mua chua, Dien Bien) and 487 (Khẩu lếch, Bak Kan) are recommended for rice breeding program for rainfed environment.

Waxy corn is commonly eaten fresh in Asian countries including Vietnam. Selection for thinner pericarp is a priority for enhancing tenderness in fresh waxy corn breeding. We have evaluated 48 of local maize cultivars and inbred lines in order to identify genetic materials that have thinner perricap for the waxy maize breeding with improved quality. The 48 cultivars and inbred lines were evaluated in the field experiment with two replication in 20012 Autumn-Winter season. Kernel pericarp thickness of cultivars and inbed lines (measured by micrometer) ranged between 51,6 to 118,9 µm. Six potential lines and cultivars with desirable pericarp thinness are D27, D34, D36, D14, D22 and D35 (D27 with 51.6 µm). Using SSR markers 28 cultivars and inbred lines were detected to have QTL controlling thinner pericarp traits. Based on phenotypic evaluatione and genetic markers, six cultivars and inbred lines, D14, D22, D27, D47, D36 and D44, possessing desirable agronomic characteristics, thinner pericarp were selected for high quality waxy maize breeding programme in Vietnam.

This study was carried out on 10 stress-negative Piétrain boars including 3 pigs of halothane genotype CC and 7 of CT at the pig breeding farm of Hanoi University of Agriculture in order to evaluate effects of season (Spring, Summer and Autumn) and halothane genotype (CC and CT) on the production performance and semen traits. The results showed that the difference in daily average gain was not significant between CC (559.57 g/day) and CT boars (546.31 g/day). The halothane genotype did not affect semen traits (P>0.05) except ejaculation volume (P<0.001). Ejaculation volume of CC genotype (270.95ml) was higher than that of CT (220.82ml). Season had significant effect on ejaculation volume, sperm concentration and pH of semen (P<0.001) as well as total number of sperms moving straight ahead per each ejaculation (P<0.05). Semen volume was highest in autumn (293.02 ml) followed by summer (195.00 ml) and spring (190.86 ml) while this tendency was inverse for sperm concentration. Total number of sperms moving straight ahead per each ejaculation was highest in autumn (47.15 billion) followed by spring (45.20 billion) and lowest in summer (36.74 billion). Semen traits of the stress-negative Piétrain boars were in accordance to the standards of technical criteria for animal breeding accoprding to the Decision No. 1712/QĐ-BNN-CN (Ministry of Agriculture and Rural development, Vietnam), except sperm motility and growth performance were lower than specified.

The study was conducted with five treatments (1, 2, 3, 4 and 5 ind./l) in order to identify the most suitable density for rearing orange clownfish larvae. Results showed that the fish reared at the densities of 1, 2 and 3 ind./l gave the highest specific growth rate (3,95; 3,87 and 3,77%/day, respectively), followed by the density of 4 ind./l (3,27%/day), the lowest at the density of 5 ind./l (2,99%/ngày); (p < 0,05). Similarly, the fish larvae reared at the densities of 1, 2 and 3 ind./l gave the highest total length (12,41; 12,09 and 11,76 mm), followed by the 4 ind./l (10,12 mm) and the lowest at 5 ind./l (9,32 mm); (p < 0,05). The fish larvae reared at the densities of 1, 2 and 3 ind./l obtained the highest survival rate (86,67; 83,33 and 78,89) followed by the 4 ind./l (55,83%) and the lowest at 5 ind./l (40,67%). In conclusion, the most appropriate density for rearing the orange fish larvae is 3 ind./l in order to optimize the growth, survival rate and economic efficiency.

The effect of stocking density of white leg shrimp SPF (Litopenaeus vannamei) was carried out at different density of 40, 60 and 80 PL15/m2 for 75 days. Each treatment was replicated three times in 4m2 indoor composite tank system and feeding ratio of 10-15% body weight with CP pellets containing 38% crude protein and four times a day. During the experiment, water temperature varied between 28 and 31ºC, whereas salinity ranged from 20-24‰ in biosecurity condition. Water in the culture tanks was renewed 50% weekly. The highest growth rate in weight was found in treatment of 40 heads/m2 (1.54 g/week), followed by 60 heads/m2 (1.47 g/week) but the rate for 30 heads/m2 (1.16 g/week) was lowest. Similarly, the survival rate of shrimp stocking at 40 heads/m2 ranked highest (79.7 ± 2.6%), followed by 60 heads/m2 (78.7 ± 2,9%) and the lowest rate for the 80 heads/m2 (70,3 ± 3,3%; P<0.05). Nevertheless, there was no significant difference in the survival rate between shrimp raised at 40 heads/m2 and 60 heads/m2 (P>0,05). Size variation (CV) for 40 heads/m2 (727 ± 1.52%) and 60 heads/m2 (8.22 ± 2.5%) were considerably lower than that for 80 heads/m2 (12.9 ±2.7%; P<0.05). However, there was no considerable disparity in feed conversion rate among the three treatments (P>0,05). All shrimp sample tissues were found negative for WSSV, YHV, TSV, MBV and IHHNV.

Nghiên cứu được tiến hành nhằm đánh giá ảnh hưởng của các thành phần di truyền Piétrain kháng stress khác nhau và mùa vụ đến sinh trưởng của lợn đực hậu bị và phẩm chất tinh dịch của chúng. Có 5 nhóm thành phần di truyền được đánh giá, bao gồm: PiDu25, PiDu50, PiDu75, PiCC và PiCT. Kết quả cho thấy, nhóm di truyền ảnh hưởng đến các chỉ tiêu sinh trưởng và phẩm chất tinh dịch. Các nhóm đực lai PiDu25, Pu50 và PiDu75 có tốc độ sinh trưởng cao hơn nhưng tỷ lệ nạc thấp hơn so với Piétrain kháng stress, ngoại trừ PiDu75. PiDu25, PiDu50 và PiCC có phẩm chất tinh dịch tốt. Mùa vụ ảnh hưởng đến hầu hết các tính trạng phẩm chất tinh dịch của đực Piétrain kháng stress thuần chủng cũng như các nhóm đực lai khác. Nồng độ tinh dịch ở mùa hè và mùa thu thấp nhất, cao hơn về mùa đông và mùa xuân. Nên sử dụng các đực lai giữa Piétrain và Durroc, đặc biệt là PiDu75 làm con đực cuối cùng.

A study was conducted to determine the effect of microbial fermented litter on reproductive performance of laying hens and reducing environmental pollution. 1,200 Luong Phuong layers from 22-45 weeks old were assigned in completely randomized design into two treatments. In the first treatment, husk litter was used as control to compare with the second treatment using microbial fermented litter. The experiment was repeated three times. Fermented litter quality including temperature, moisture, number of total aerobic bacteria, and barn microclimate, as well as production parameters were evaluated. The results showed that the temperature was increased while moisture was reduced in chiken house when microbial fermented litter was used. The concentration of CO2and NH3reduced signifcantly in treatment using microbial fermented litter compared with control (P<0,05). During the experimental period, the average egg production (hen-day %) and FCR(kg feed/10 eggs) of the hens were not significantlty different among treatments. However, using microbial fermented litter clearly reduced disease incidence and mortality rate in treatments (P<0,05). Based on this study it could be concluded that microbial fermented litter could be utilized for laying hens to reduce environmental pollution.

The study was carried out at 3 pig farms in Hai Dương and Hưng Yên from March 2011 to January 2013 to evaluate growth rate and carcass quality of F1(Landrace x Yorkshire) (F1(L x Y)) sows mated with F1(Piétrain x Duroc) (PiDu) boars with Pietrain ReHal genetic constitution (25, 50 và 50%: PiDu25, PiDu50, PiDu75). The results showed that these crossbreds obtained high growth rates and low feed conversion ratio (FCR) (829.42 g/day and 2.31 kg/kg; 797.78 g/day and 2.33 kg/kg; 765.79 g/day and 2.38 kg feed/kg weight gain, respectively). Lean meat percentage of PiDu25 x F1(L x Y), PiDu50 x F1(L x Y) và PiDu75 x F1(L x Y) were 54.66, 56.32 and 59.97 %, respectively. Lean meat percentage of PiDu75 x F1(L x Y) was higher than that of PiDu25 x F1(L x Y) and PiDu50 x F1(L x Y). The meat quality traits in terms of pH, colour drip loss, and firmness of 3 crossbreds were normal. Crude protein of musculus longissimus dorsi of crossbreds was 21.53, 22.18 and 22.63%. The research suggests that using crossbed boars PiDu25, PiDu50, PiDu75 to mate with F1(L x Y) sows helps to obtain high performance in pig farms.

Magnetic CoFe2O4/bentonite nanocomposite was synthesized by chemical co-precipitation method. It has a large surface area of 380 m2/ g. Absorption ability of CoFe2O4/bentonite was studied on methylene blue solution. The factors that affected the absorption process, such as absorption time, temperature and pH were researched. The results showed that at 50mg/l of methylene blue solution and pH= 7-8, the absorption efficiency of CoFe2O4/bentonite for methylene blue was highest with the value of 95,0 -95,1%

Bài viết nghiên cứu mối quan hệ giữa việc làm phi nông nghiệp và thu nhập hộ gia đình vùng ven đô Hà Nội. Kết quả chỉ ra rằng phần lớn các hộ gia đình trong mẫu khảo sát tham gia vào hoạt động kinh tế phi nông nghiệp và thu nhập từ hoạt động này đóng góp phần lớn cho thu nhập của các hộ. Các nhân tố tác đông tới thu nhập hộ gia đình được nghiên cứu bằng việc sử dụng mô hình hồi quy đa biến và kết quả đã khẳng định tầm quan trọng của việc làm phi nông nghiệp trong việc nâng cao thu nhập hộ gia đình. Bên cạnh đó, chúng tôi phát hiện rằng một vài biến số khác như giáo dục, tiếp cận tín dụng, đất đai và tài sản sản sản xuất có tác động tích cực tới thu nhập hộ gia đình. Dựa vào kết quả thực nghiệm, bài viết đề xuất một vài hàm ý chính sách có thể giúp nâng cao thu nhập của hộ gia đình.

The Northern Mountainous Region is characterized by a high density of ethnic minorities , topographical ruggedness and high poverty rate. A number of poverty reduction programs/projects was implemented with specific activities. However, the assistances are not the universal key for poverty reduction that requires, more than anything else, the efforts of communities. In the present paper analyses the current status and points out factors affecting the participation of ethnic communities in poverty reductions activities. Measures to be taken are proposed including revision of policies, renewing the ways of community mobilization, better information exchanges and human capacity building for ethnic minority’s staff in order to better mobilizing the participation of communities in poverty reduction efforts.

Economic Recession (ER) is an essential phase of economic cycle. The 2008 - 2009 economic recession had a strong impacts on the economy in general and the business activities of enterprises in particular. The main objective of this study was to analyze the effect of ER on business activities and workers’ life of some representative enterprises in the North of Vietnam, and propose some key sulutions to minimize the negative impacts of ER and improve the adaptability of enterprises to recession conditions. The systematical and participatory approaches were used. Data collection and analysis used in this study were data synthesis, direct survey of representive companies in the North using questionaire, consultancy, and comparision methods. The study showed that enterprises have been clearly impacted by the ER in all production and business processes. The main impacts were high input prices, limited resources, difficulties in labor and loans, instability in production and consumption and decline in the enterprise performance. To minimize these negative impacts, enterprises should apply multiple solutions and at the same time with the government supports.