Tập 15 Số 3 (2017)

Nghiên cứu này được tiến hành nhằm đánh giá ảnh hưởng của lượng đạm bón đến sự phát triển bộ rễ được thể hiện qua tổng số chiều dài rễ, số rễ mọc từ mắt thân, chiều dài rễ mọc từ mắt và chiều dài rễ bên; lượng nước cây sử dụng và khả năng tích luỹ chất khô trong điều kiện độ ẩm đất khác nhau. Lúa được trồng trong hộp nhựa quan sát được sự phát triển của bộ rễ trong điều kiện nhà có mái che. Thí nghiệm gồm ba mức độ ẩm đất: tưới nước ngập (CWL), điều kiện thiếu nước (WD) ở 25 và 20% w/w độ ẩm đất. Thí nghiệp áp dụng 3 mức phân đạm bón: 30, 60 và 120 mg N cho mỗi hộp. Phân đạm được trộn đều với 80 mg P2O5 và 70 mg K2O và 2.5 kg đất khô trước khi gieo hạt. Kết quả thí nghiệm cho thấy, trong điều kiện thiếu nước (ở cả 25 và 20% w/w độ ẩm đất), khi tăng lượng đạm bón từ 30 lên 60 mg N đã làm tăng các chỉ tiêu về rễ, lượng nước cây sử dụng và khối lượng chất khô của cây, nhưng không có sự khác nhau về các chỉ tiêu trên khi tăng lượng đạm bón từ 60 lên 120 mg N. Tuy nhiên, trong điều kiện tưới ngập, các chỉ tiêu về rễ tăng dẫn đến cây hút được nhiều nước hơn, kết quả cây tích luỹ chất khô cao hơn khi tăng lượng đạm bón từ 30 lên 120 mg N. Hơn nữa, trong cả điều kiện tưới ngập và thiếu This study was conducted to evaluate the effects of nitrogen (N) application on root system development, expressed as total root length, nodal root number, nodal root length and lateral root length, in addition to water use and dry matter production under different moisture soil conditions. The rice plants of Nipponbare, a Japanese rice cultivar, were grown in a PVC rootbox (25 cm × 2 cm × 40 cm, L × W × H) under a vinyl house. There were three moisture treatments: continuously waterlogged (CWL) condition and two water deficit (WD) conditions as 25% w/w and 20% w/w. The N fertilizer (urea: 46%N) was applied at three different levels: 30, 60 and 120 mg N rootbox-1. Each level of N fertilizer was thoroughly mixed with 80 mg phosphorus, 70 mg potassium and 2.5 kg air-dried soil per rootbox prior to seed sowing. The obtained results showed that increasing the N level from 30 to 60 mg N rootbox-1 increased root system development (as total root length, nodal root number, nodal root length, and lateral root length), water use, and shoot dry weight of Nippobare under WD conditions (at both 25 and 20% w/w of soil moisture content (SMC)), but there was no significant difference in the above traits between the 60 to 120 mg N rootbox-1 treatments. Under CWL conditions, however, the above root traits increased significantly after increasing the N application from 30 to 120 mg N rootbox-1, which led to an increase in water use, and eventually a significant increase in dry matter production. Furthermore, increasing the N application levels increased water use through increased total root length, which led to the positive and notably significant correlation between the total root length and water use under both CWL and WD conditions., tổng số chiều dài rễ có mối quan hệ thuận và chặt ở mức có ý nghĩa với lượng nước cây sử dụng.

Hydroponic and field experiments were conducted to evaluate the effect of three nitrogen (N) supplies and two N forms - ammonium nitrate and urea - on growth of rice plant under severe saline conditions. In hydroponics, two salt tolerant cultivars, Cuom and A69-1, were examined at tillering stage. Three concentrations of N - 1.4, 2.1 and 2.8 mM were applied in the Yoshida solution supplemented with NaCl at 113 mM. In paddy field under severe saline condition, six cultivars, viz. Cuom, Ngoi, Hom rau, A69-1, FL478, and IR28 were used to evaluate growth and yield at three N supplies, 45, 68 and 90 kg N ha-1. In hydroponic conditionplant dry weight, number of root tips, total root length, and SPAD value increased with ammonium nitrate concentration.In contrast, all these parameters as well as leaf specific area and N use efficiency decreased with urea concentration in both of cultivars. In the paddy field experiment, N forms and levels had no effect on grain yield, but N forms affected 1000-grain weight and number of panicles per plant, whereas N levels increased dry matter weight at dough-ripening stage with N applied. The use of reduced level of N fertilizer is suggested for rice under severe saline condition.

The expression and inheritance of various agronomic traits were studied inF2 mungbean population from the cross Berken/DX92-1 and its parents. Segregations were observed in all measured traits in F2 population. Qualitative traits including morphological and visual seed traits exhibited single or two gene models depending on circumstances. Single gene model included leaf color, flower color, seed color, hilum color, seed shinness, and pod shape; two gene model included seed shape, pod color, and stem color. There were no significant differences in phenological traits between parents, resulting in low variation in F2 progeny. The growth duration of F2 progeny was in the range of 71 - 76 days, indicating short growth duration. For most quantitative traits, the means of morphological, vegetative and yield related traits were higher than parents. There were transgressive segregations for leaf size, pod size, seed yield, and pod dry mass. The coefficients of variation varied from 0.9 - 40.5%. Low broad-sense heritability estimates, 2.2 - 59.8%, for most traits indicated large environmental effects on trait expression. The exceptional traits included leaflet and pod width with high broad-sense heritability of 90.4% and 97%, respectively while individual seed yield and standing dry biomass with average broad-sense heritability of 64.9% and 66.8%, respectively. Average seed yield of F2 population was similar to Berken but some individuals exhibited higher seed yield than Berken which could be further advanced and studied.

Immunostimulants are the substances, which enhance the immuno-defense activity and provide resistance to fish and shrimp diseases. In order to clarify the lysozyme expression of kuruma shrimp (Marsupenaeus japonicus) after feeding immunostimulant, the supplement containing microalgae and Euglena (Ex400) were selected for the trials. Total RNA was extracted by RNA Iso Plus from the lymphoid organ, intestine and blood of shrimp that was fed with Ex400 diet. Tissues were sampled at 0, 3, 7, and 10 days after feeding. Lysozyme transcripts significantly increased in Ex400-fed shrimps compared to control diet-fed shrimps (P < 0.01) at 7 and 10 days post-feeding in lymphoid organ and intestine. Lysozyme expression of blood of shrimp also exhibited higher level than those of control at 3 and 10 days post feeding (P < 0.01). In conclusion, the result of lysozyme gene expression suggested that immunostimulant could activate lysozyme in the immune system of kuruma shimp.

The aim of the present study was to examine the association of polymorphisms in the small nuclear RING finger protein (RNF4), retinol binding protein 4 (RBP4) and the insulin-like growth factors 2 (IGF2) genes with reproductive traits in Landrace and Yorkshire sows. A total 393 sows (188 Landrace and 205 Yorkshire) were genotyped using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The results found that the polymorphic sites of two polymorphisms in the RNF4 and RBP4 genes were found in both breeds (RNF4: TT, TC and CC; RBP4: AA, AB, BB genotype; IGF2: AB and BB), except the genotype AA of IGF2 was not observed in Yorkshire sows. The polymorphisms of RNF4 showed a significant association with total number of piglets born and the number of piglets born alive in both Landrace and Yorkshire sows (P < 0.05). Sows with the CC genotype produced more piglets than TT genotype. A significant association of the RNF4 polymorphism with total litter weight of piglet born was also observed in the Landrace sows (P < 0.05). For the RBP4 gene, there was a significant association between the genotypes with the number of piglets borm, total number born alive, and total litter birth weight in Landrace sows (P < 0.05). No significant association of the IGF2 polymorphism with any reproductive traits was observed in either Landrace or Yorkshire sows (P > 0.05). These results indicated that the RNF4 and RBP4 genes can be used as candidate genes for improvement of litter size traits in pigs.

Classical swine fever (CSF), a highly infectious viral disease of swine, has caused great economic losses to the swine industry worldwide. Previous reports showed that CSF virus (CSFV) circulating in the Mekong delta area of South Vietnam between 2002 and 2003 belonged to group 2. In this study, to identify the predominant CSFV strains currently circulating in North Vietnam, the full-length E2 gene of five CSFV isolates collected from Hai Duong and Nam Dinh provinces of Vietnam in 2014 were sequenced and analyzed. The results of nucleotide (nt) and amino acid (aa) comparison showed that the 5 field CSFV isolates in this study shared 85.5 - 99.7% nt and 92.7 - 99.7% aa identity. Phylogenetic analysis of the complete E2 gene sequences revealed that the CSFV isolates collected from two farms (one in Ninh Giang - Hai Duong and one in My Xa - Nam Dinh) belonged to subgroup 2.1, whereas CSFV isolates collected in the Xuan Truong - Nam Dinh farm clustered within subgroup 2.2.

This study aims to find out the nature of land use management practices and their impacts on the efficiency of agricultural land use in Son Tay town. Proportional random sampling was used to select 160 households from 4 communes, which represented two areas. Data were gathered through individual face-to-face and in-depth interviews, and from secondary sources. Data were analyzed using the 5-points Likert scale to assess the level of land use management. Using analysis of variance (ANOVA) and LSD’s post-hoc multiple comparison to test the differences between some indicators among land users and between the 2 regions. The efficiency of agricultural land use was measured in terms of economic and social aspects. They were value added (VA) per hectare, laborers per hectare, and VA per laborer. The impact of land use management on the efficiency of agricultural land use was analyzed by using the Spearman rank correlation coefficient in SPSS17.0 with a significance level of 0.05. The results of the research showed that the local people realize that there have been remarkable changes in the land use management recently. There were moderately positive impacts of land use management in terms of organizing the implementation of legal establishment documents; land use planning, management of land use planning and plans for land use; allocation and management of the implementation of land use rights; and land valuation on the efficiency of agricultural land use. Otherwise, there was a moderately negative impact of land use management in terms of the real estate market information on the efficiency of agricultural land use.

The objectives of the study are to assess the land use change and interaction among soil-water resources and rural livelihoods of Hoa Binh province in Northwestern Vietnam. The land use change was investigated for three time periods using the remote sensing data acquired in the years 1995, 2005, and 2010. The results show that the major land use types with the most significant changes occurring in the five land use classes were: barren land (BRNL), disturbed forest (DTFR), field crop (FCRP), paddy (PDDY), undisturbed forest (UDFR), and urban (URBN). From 1995 to 2005, the proportional extent of FCRP, PDDY, and URBN, was from 5.36% to 11.89%, 10.91 to 15.66, and 5.98 to 8.48%, respectively. On the other hand, the proportion of DTFR and UDFR dramatically decreased from 22.92% to 14.32%, and 30.61% to 24.43%, respectively. Main factors influencing land use decision and crop systems are government policies and commodity prices. Considering soil erosion and water related impacts, expansion of agricultural activities as well as deforestation were causes of increased surface flow and soil erosion, and nutrient losses. The overall livelihood index was 0.514 indicating that the livelihood of the households in the study area is at or above average and there were no significant differences between groups; however, calculated livelihood index indicated that farmers in Cao Phong district have higher overall livelihood indices compared to other households in the area.

Bacterial leaf streak (BLS) disease in rice, caused by Xanthomonas oryzae pv. oryzicola (Xoc), has become a more common and serious disease in tropical regions along with bacterial leaf blight. Breeding new rice varieties by introducing resistance genes is considered one of the most effective and eco-friendly ways to control the disease. With a high diversity of resistance genes, local rice varieties play an important role in developing durable resistant varieties against diseases. In this study, 50 local rice accessions provided by Center for Conservation and Development of Crop Genetic Resources (CCD-CGR) were used to evaluate the reaction pattern with two isolates Xoc, TB4 and TN158. Lesion lengths measured after artificial inoculation showed 3 highly resistant (HR) accessions and 15 resistant (R) accessions to both TB4 and TN158 isolates. Four pairs of flanking SSR markers, RM587, RM510, RM153, and RM159, were used to detect the bls1 and qBlsr5a genes. The results of genotyping revealed 6 accessions containing the bls1 gene and 6 accessions containing qBlsr5a, of which, accession 11189 contained both genes. Based on the correlation analysis between reaction patterns and genotypes, the resistance ability of the bls1 gene was highly effective to Xoc, while the qBlsr5a gene did not show clear resistance. With our results, accessions that were HR or R, and carried the bls1 gene could be used as donors for breeding new rice varieties resistant to BLS.

Creation of land funds in Thai Nguyen city from 2004 - 2015 was performed through two forms: 1) the State recovers land and then the State or direct allocates lease land to investors, or they allocate and lease land to investors through auctions on land use rights, with investors bidding for land use projects, and 2) direct agreements between the investors and land users, with a total area of 9,061,339.96 m2 for 624 projects. The form of land fund creation by recovery from the State’s was the dominant method accounting for 93.75% of the total number of projects and about 97% of the total area of land fund created. Research of the factors affecting the creation of land funds in Thai Nguyen city, 22 factors were identified, which were divided into 5 groups of factors (independent variables): social economic; natural conditions and infrastructure; legal policy; finance; and planning. Three groups factors evaluating the results of land fund creation (dependent variables). Five hundred people (officials, organizations and households) related to the creation of land funds were interviewed with the pre-designed questionnaire to collect information about the aforementioned variables. Collected data was processed in the statistical software SPSS, the consistency coefficient measured with Cronbach's Alpha for scaling test, and Exploring Factor Analysis (EFA) was used. Among the influencing factors of land fund creation, the land price factor, the state budget in advancing to the creation of land funds, policies of attracting investment, and the urbanization process have the greatest influence. Some solutions to enhance land fund creation in Thai Nguyen city in the future were proposed as follows: Thai Nguyen province People's Committee should determine specific land prices in line with the social economic and natural conditions to help land recovery is done on schedule. Thai Nguyen city People's Committee should pay attention to the policies of attracting investment, especially investment projects relevant to land use, and propose specific mechanisms of attracting investors in line with social economic development in city.

Plantago major L., a species that originated in the Far East, has been used for medicinal aspects since ancient times. The technique for callus induction, growth, and plant regeneration from cultured young leaves and petiole explants of Plantago major was carried out. The best initiation and growth of calli was achieved on MS supplemented with 1 mgL-1 2,4-D and 0.5 mgL-1 BA. Shoot regeneration from the calli was obtained on MS medium containing 1 mgL-1 TDZ alone or combined with 0.5 mgL-1 α-NAA (100 and 96%, respectively). Moreover, the optimum medium for shoot multiplication was MS medium comprising 5 mgL-1 BA, and root formation from the shoots was half-strength MS medium supplemented with 2 mgL-1 NAA. The regenerated plants were successfully transferred into pots containing a mixture of decayed straw: rice husk ashes, (1:1, v/v), sand: soil (1:1, v/v), soil, or sand and grown in nethouse. The phenotypes of regenerated plants were normal as a mother plant.

In this study, MnO2/Al2O3 catalysts were synthesized from manganese acetate and aluminum hydroxide by the sol-gel method at room temperature, followed by thermal treatment at 300°C. The characterization of the product was performed by X-ray diffraction (XRD), energy dispersive analysis of X-rays (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET). The ozonation of methylene blue (MB) solution in the presence of MnO2/Al2O3 catalyst was investigated in a laboratory scale batch reactor. The effect of pH solution (2-12), reaction time (0 - 60 minutes), and MnO2/Al2O3 catalyst dosage (0 and 0.1 - 5 g.L-1) on MB treatment was determined. The results showed that the reaction with the presence of catalyst required less time and improved the reduction level of MB compared to conventional ozonation. The optimal pH and catalyst dosage values were 8 and 1 g.L-1, respectively. For textile dyeing wastewater treatment, the catalytic ozonation decreased the color scale from 7693.89 Pt-Co to 28.40 Pt-Co and COD from 387.60 mg.L-1 to 52.35 g.L-1. Therefore, the ozonation with MnO2/Al2O3 catalysts can be considered as effective and feasible for treating the textile dyeing wastewater.

Phytases are a group of enzymes that hydrolyze phytate to release inorganic phosphate and myo-inositol phosphate intermediates. The phytase encoding gene (phyL) of Bacillus licheniformis DSM13 is strongly induced during phosphate starvation conditions. In this study, we analyzed the activity of the phytase promoter by constructing a recombinant strain containing a plasmid bearing the phyL promoter fragment and the reporter gene xynA (encoding the xylanase) fusion. The recombinant strain was grown in conditions without and with the addition of different concentrations of sodium phytate. The results showed that the phytase promoter was strongly induced when less than 5 mM of phytate was added to the growth medium. Furthermore, growth analysis experiments revealed that phytate was an important alternative phosphate source for B. licheniformis cells to overcome phosphate starvation conditions.

The paper presents a wireless monitoring system to measure environmental parameters. In this context, we proposed a wireless air temperature and humidity monitoring system which is low-cost and easy for Vietnamese to use. The system consists of an 8-bit micro chip professional ATmega8 as the core control of the system, wireless transceiver module nRF24L01, and temperature and humidity sensor DHT11. Interface monitoring software was designed by Visual Studio. To assess the accuracy of the measuring equipment, thermometer and hygrometer DC107 was employed for standards. The air temperature and humidity data at the wireless monitoring system were highly comparable to those of the DC107. Energy saving solutions for remote equipment are also mentioned in this study.