Vol. 13 No. 2 (2015)

Successful nitrogen management supplies enough nitrogen to the crop to optimize performance and profitability while minimizing losses to water and air. The present experiment was conducted to investigate the effect of fertilizer placement distance and depth of granular or slow-release nitrogen on growth and yield of C919 corn hybrid in 2012 winter 2013 spring seasons in Vinh Loc district, Thanh Hoa province. All experimental plots were applied with 8 tons of manure, 120 kgN in granular form, 90 kgP2O5, 90 kgK2O per hectare basis. Twelve treatment combinations of three placement distances and 4 depths of granular nitrogen fertilizer application was arranged in a randomized complete block design with three replications. The results showed the depth and placement distance of slow-release nitrogen fertilizer did not affect growth duration of maize C919 in both growing seasons but leaf area index, dry matter accumulation, yield components and grain yield. Highest grain yield was obtained when slow-release N fertilizer placed at 10 cm from the plant and 10 cm deep in the soil.

This study evaluated growth and yield of two quinoa genotypes in winter-spring and spring-summer growing seasons under different levels of nitrogen fertilizer applied to determine growing season and dressing dose for quinoa production in the Red River Delta, Vietnam. The field experiment was a split-plot design with three replications. The main factor consisted of four nitrogen levels: N1- 0kg N; N2- 30kg N; N3- 60kg N và N4- 90kg N/ha ( winter - spring season) and N1- 30kg N; N2- 60kg N; N3- 90kg N và N4- 120kg N/ha (spring - summer season). The sub-factor consisted of two quinoa genotypes of Chilean origin, Green and Red quinoa. Data were collected for growth duration, plant height, stem diameter, dry matter accumulation, chlorophyll index (SPAD meter), lodging tolerance, pests and diseases, number of panicles/plant, number of grains/panicle, 1000 grain weight and grain yield. Increased nitrogen levels prolonged crop duration in spring - summer season only but increased dry matter accumulation, number of grains/panicle, 1000 grain weight and grain yield of both quinoa varieties in both growing seasons. Application of 90kg N/ha appeared as optimal dose for growth, development and yield of quinoa varieties in both growing seasons. The results showed that winter - spring season was favorable for growth and grain yield in the Red River Delta.

Twenty chromosome segment substitution lines (CSSLs) developed from IR24 background (5 lines of Ruf ILs (IR24 × O. rufipogon), 15 lines of IAS (IR24 × Assominori - a Japonica cultivated rice) and IR24 were evaluated for drought tolerance at tillering stage. The 3-leaf seedlings were grown in Kimura B + 20% PEG6000 solution (drought treatment) or in Kimura B solution (non-drought treatment). The results showed that, the drought resistance index (DRI) correlated with the dry matter under drought and non-drought conditions with r = 0,614 and r = 0,604, respectively. The number of leaves, leaf area, root surface area, number of roots and root hairs in both CSSLs and IR24 were reduced in drought condition. But, there was no reduction in root numbers and root hairs numbers in CSSLs, which had higher DRI. The results also showed that, drought tolerance mechanism of IAS lines might involve the increase of root growth, water uptake and root-to-shoot water transport. However, the mechanism in Ruf ILs lines might involve the reduction of leaf number, leaf area and in company with increase of root growth and water uptake. These finding suggested that wild rice O. rufipogon and Asominori would be ideal materials for rice breeding for drought tolerance.

Drought is an environmental factor that adversely affects growth and development of tomato. These experiments were designed to estimate drought tolerance of two tomato varieties (PT18 and VL3000) through physiological parameters and proline content at flowering and young fruit stages. The results showed that leaf relative water content (LRWC) and chlorophyll content of PT18 and VL3000 decreased and had lower level at both flowering stage and young fruit stage in comparison with the control. Proline content, in contrast, increased significantly at flowering and young fruit stage when exposed to water deficit.. PT18 appeared to be better drought tolerant than VL3000.

Leaf eating moth Hypocala subsatura Guene (Lepidoptera: Noctuidae) is main insect pests on imported sweet persimmon MC1 (Fuyu) in Hoa Binh, Viet Nam. The catepillars can cause severe yield losses in sweet persimmon by damaging new flushes. Six to twelve hours after hatchment mating occurred and mostly took place during night time. Addition of 10% honey to feed, the longevity of female last to 13.5 days, longer than male (about 12.2 days). Pre-oviposition period was 2 days; oviposition period was recorded highest during 4, 5 and 5 days; post-oviposition period was 1-2 days (at 28°C and 70%). Eggs were laid singly on the young leaf surface of the branches which are not affected directly by the sun. The first, second and third instars live in group but 4th and 5th instars start to spread out to the midribs of large leaves and young shoots. 70% of larvae pupated on the soil surface in the cocoons made from dead leaves and other plant debris while 26.67% pupatedin soil at a depth of 0-3cm and 3.33% pupated at the depth of more than 3cm in the soil.

Effects of stocking densities on the growth, survival rate and production efficiency of Meretrix lyrata commercial culture were investigated out in 500 square meter earth pond. Clam seeds (2.45±0.08g in body weight) were stocked at densities of 90, 150 and 210 individuals/m2and reared in a period of 12 months. Results showed that stocking densities did not affect the concentrations of DO, pH, NH4+and chlorophyll-a in culture ponds (P>0.05). Growth rate (0.57-0.60 %/day) of clam reared at 90-150 individuals/m2was significantly (P<0.05) higher than that at 210 individuals/m2(0.48 %/day). In contrast. clam productivity was higher at stocking densities of 150-210 individuals/m2(26.4-27.0 ton/ha) than at 90 individuals/m2(18.8 ton/ha). Survival rates were inversely propotional to stocking densities. The highest profit (138.6 million VND/ha) and benefit-cost ratio (32.13%) were observed at 150 individuals/m2and the lowest values (33.4 million VND/ha and 9.01%, respectively) at the density of 210 individuals/m2. This study suggests that the suitable stocking density in the earth pond culture of M. lyrata should be is 150 individuals/m2.

Yếu tố nhân kappa B (NFκB) đóng vai tròquan trọng trong hệ miễn dịch của các loài sinh vật. Trong nghiên cứu này, tính chất hóa lý và cấu trúc phân tử protein NFκBIα củamột số loài cánhư cá bảy màu (Poecilia reticulate), cá rạn (Stegastes partitus), cá nheo Mỹ (Ictalurus punctatus), cá vây tay (Latimeria chalumnae), cá mập ma (Callorhinchus milii)được phân tích bằng phương pháp in silico. Kết quả nghiên cứu đã ghi nhậnđiểm đẳng điện lý thuyết(pI: 4.37 – 5.09), hệ số tắt(EC: 17920– 37650 / 17420 – 36900),chỉ số béo(AI: 85.88 – 98.83),chỉ số bất ổn định(II: 39.83 – 49.09), tổng số dư lượng điện tích âm (-R:47 – 55)và điện tích dương(+R: 19 – 29), hệ số GRAVY (-0.611 – -0.241)của phân tử protein NFκBIα trên cá. Ngoại trừ protein của cá bảy màu, tất cả các protein còn lại là protein dễ tan. Axit amin cysteine và các liên kết cysteine dược ghi nhận hiện diện trên tất cả các chuổi protein. Ở cấu trúc bậc hai, số lượng dạng xoắn (helices)và xoắn ngẫu nhiên (radom coils) với số lượng tương đương chiếm ưu thế và tiếp sau làdạng sợi (strands). Cấu trúc 3D của phân tử protein được thực hiện và được đánh giá là phù hợp cho phân tử protein NfκBIαthông qua kết quả kiểm định bằng chương trình PROCHECK Ramachandran, ProQ và ProSA.

Tế bào hình chén đóng vai trò quan trọng trong việc thải trừ giun Nippostrongylus brasiliensis (N. brasiliensis) thông qua việc tăng số lượng tế bào và tăng tiết chất nhầy ở ruột. Trong khi đó, cầu trùng Eimeria vermiformis lại làm giảm số lượng tế bào hình chén ở ruột và hình thành miễn dịch tế bào Th1 ở ruột thì N. brasiliensis lại sản sinh đáp ứng miễn dịch Th2. Bài báo này sẽ thảo luận những ảnh hưởng gây ra do tế bào hình chén ở chuột đồng nhiễm trong việc thải trừ N. brasiliensis. Nippostrongylus brasiliensis và Eimeria vermiformis được gây nhiễm cho chuột ICR. Kết quả cho thấy, việc thải trừ giun bị giảm ở chuột đồng nhiễm so với chuột đơn nhiễm và có liên quan đến số lượng của tế bào hình chén. Kết quả này cho thấy, Eimeria vermiformis có ảnh hưởng đến việc thải trừ Nippostrongylus brasiliensis và có thể thông qua hệ đáp ứng miễn dịch ở chuột đồng nhiễm.

Fingerling fish quality in aquaculture is an issue of great concern by the Fisheries Sector. Specifically, the grass carp, a traditional species raised in fresh water, is more likely infested with parasites in the fry and fingerling stages. In the present study 900 Grass carp at fry and fingerling stages collected from 30 fish ponds in BacNinh and Hanoi provinces were treated with Praziquantel and Mebendazole against parasites by oral and immersion methods using three doses (5; 10 and 15 ppm for immerse method; 25; 50 and 75 mg/kg of fish bodyweight for oral method) in three days. The drug experiment was carried out in 38 tanks of 80 x 50 x 40cm3 with 1,140 fish at 1.89 g/fish. Each tank contained 30 fish. The result showed that two kinds of drug and two methods of treatment were effective against monegenea and metacercaria of digenea in Grass carp with dose of 15ppm for immerse method and 75 mg/kg of fish bodyweight for oral method.

Community based ecotourism will contribute to ensure sustainable socio-economic development, integration and cross-cultural intersection. The research was conducted in Giao Thuy district where attractive natural scenes and charming relics are located. Surveying 400 tourists and 400 individuals engaging in tourism services showed that visitors highly appreciated historical relics and reserved natural areas of the district. The related infrastructure, hotel accommodation, food services are in well rated. However, visitors were concerned about the comfort and facilities, response to errors in service and feedback to tourists’ questions, sanitary condition, security and asset protection during visit to Giao Thuy district. In the period of 2000-2012, as the result of community based eco- tourism, the land allocated for that purpose increased to 636.24 hectares. In order to develop community based eco-tourism, the following solutions were proposed: rational tourism resource use planning, appropriate policies, increased advocation and full use of local resources.

This study was carrried out to determine the relationship between carbon (C) stock and people’s livelihoods. The analyzed results from 100 questionaires and group discussions at two villages which belong to Con Cuong district, Nghe An province showed that the livelihoods of the local people are very poor. The current land use types with high economic benefits resulted in low C stock. In contrast, the primary forests which arerich in C do not provide high incomes to the farmers. Policies on land management, forest protection, and forest plantation strongly impact people’s livelihoods. Due to the strict forest protection regime and the ban on shifting cultivation, farmer’s incomes have been significantly decreased at the strudy areas. Forest plantations are still financially supported by the government, but only a few better off households can afford to plant trees on their allocated forest land. Diversifying livehoods for local farmers by establishing an agroforestry model of field crops, such as cassava, inter-planted with tree crops such as fruit trees and Acacia sp., while continuing to protect upstream forests, could lead to the increase of C stocks and help poor farmers, but this measuere is only feasible if financial support is provided to the poor households.

Recently, Genome-wide association studies (GWAS) have been successful in the identification of genetic variants that have effects in some complex diseases. Most GWA studies used single SNP (single-nucleotide polymorphism) approaches that mainly focused on assessing the association between each individual SNP and the disease. However, in fact, complex diseases are thought to involve complex etiologies including complicated interactions between many SNPs. Thus, different approaches are necessary to identify SNPs that influence disease risk jointly or in complex interactions. Random Forest (RF) method recently has been successfully used in GWAS for identifying genetic factors that have effects in some complex diseases. In spite of performing well in terms of prediction accuracy in some data sets with moderate size, RF still suffers from working in GWAS for selecting informative SNPs and building accurate prediction models. In this paper, we propose a new two-stage sampling method in learning random forests. The proposed method allows to select a sub-set of informative SNPs which are most relevant to disease. Therefore, it reduces the dimensionality and can perform well with high-dimensional data sets. We conducted experiments on two genome-wide SNP data sets to demonstrate the effectiveness of the proposed method.

Like bio-diversity, there are too many proteins to experimentally annotate. Thus, methods for predicting the functions of proteins become necessary. In this article, we proposed a method that uses biological data to classify membrane transporters according to transported substrates. Motivated by the concept of Operons, our method used expression data and GO terms of neighboring genes to create input data for support vector machine. To rapidly obtain the result, we integrated LIBSVM in our tool then used this tool to train and test our classifiers. With this tool, users can classify membrane transporters and other kinds of proteins. This tool also allows users to add their desired organisms beside our tested ones.

Phương pháp nuôi cấy bao phấn được ứng dụng rộng rãi trong tạo cây vô tính. Nghiên cứu của chúng tôi đã tiến hành đánh giá ảnh hưởng của giai đoạn phát triển của hạt phấn, chất điều tiết sinh trưởng, sự tương tác giữa tuổi mô sẹo và nuôi trường nuôi cấy đến sự tạo cây vô tính ở cây dâu tây phản ứng trung tính với ánh sáng. Thêm vào đó, chỉ thị phân tử SSRs cũng được khảo sát để xác định cây tái sinh đồng hợp tử. Hạt phấn ở giai đoạn đơn nhân đã cho sự phản ứng tốt nhất. Hầu hết mô sẹo thu được trên môi trường Dumas De Vaulx (C – medium) chứa 0,4 mg benzyl adenine (BA) + 0,1 mg 3-indole acetic acid (IAA) + 2,0 mg 2,4-Dichlorophenoxyacetic acid (2,4-D). Tổ hợp chất điều tiết sinh trưởng (1 mg BA + 2 mg IAA) trong môi trường MS cho tỷ lệ cây tái sinh cao nhất (10,0%). Sự kết hợp giữa môi trường Gamborg (B5) và mô sẹo 2 tháng tuổi đã cho số mầm tạo thành cao nhất (7,1 mầm). Phân tích độ bội của cây tái sinh bằng đếm nhiễm sắc thể cho thấy 50% là cây bát bội, 10% cây lục bội, 35% cây lệch bội và 5% cây tứ bội (đơn bội). Sử dụng 30 bộ mồi SSRs, chúng tôi nhận thấy 10 cây bát bội được hình thành từ bao phấn giống cây mẹ hoàn toàn về di truyền. Kết quả đã chỉ ra rằng không có cây đồng hợp tử được tạo ra trong nuôi cấy bao phấn. Điều này đã chứng thực rằng tất cả cây tái sinh được hình thành từ tế bào sinh dưỡng. Chính vì vậy, nuôi cấy bao phấn có thể là phương pháp hiệu quả mới trong tạo cây đơn bội và nhân nhanh trên cây dâu tây phản ứng trung tính với ánh sáng.

In order to produce a Dendrobiumlinesresistant toCyMV (Cymbidium mosaic virus), protocorm like bodies (PLBs) of DendrobiumSoniawere infected with Agrobacterium tumefaciensC58 carrying plant transgenic vector pK7GWIWG2 (II)/CP, containing RNAi structure of coat protein gene (CP) alone or in combination with ORF2-4 gene of CyMV. The transformed PLBs were disinfected with cefotaxime 300mg/l and screened for kanamycin 500mg/l. Viable PLB-derivedlines were obtained after the screening. The presence of the target gene in these lines was confirmed by PCR.

Hàm lượng phenol tổng số và độ màu của mật chè tinh được phân tích trong 5 tháng mùa vụ sản xuất. Kết quả cho thấy có mối tương quan thuận giữa hàm lượng phenol tổng số và độ màu của mật chè. Sự ảnh hưởng của thời gian lưu trong thùng chứa và độ pH của mật chè đến sự thay đổi độ màu của mật chè cũng được phân tích nghiên cứu. Kết quả cho thấy độ màu mật chè tăng lên đáng kể theo thời gian lưu đặc biệt trong môi trường mật chè có độ acid cao (pH thấp).

This study was carried out to induce the hairy roots of Salvia miltiorrhizaBunge using Agrobacterium rhizogenesand investigate factors affecting growth of hairy root in culture. Among three explants (leaf, petiole and stem), leaf was found to be the most efficient explant for transforming and inducing hairy roots. Inoculation of leaf explantswith concentration of ATCC 15834 strain at optical densiy of 600nm (OD600) = 0.2 indicated maximum percentage (53,85%) ofroot induction. PCR analysis using specific primers for rolAgene confirmed the presence of the rolAgene in four hairy root lines. These hairy root lines showed fast and stable growthon hormone-free B5 medium. Between two media tested, B5 medium sustained better hairy root growth of A5.14 line than MS medium. Hairy root growth in B5 solid medium yieldedmaximum root biomass (7,67- fold higher) in 4-weeks compared to liquid, semi-liquid and double layered medium.

The experiment was carried out to examine the anti-bacterial effects of essential oil from perilla leaves on eight spoilage and food poisoning bacteria strains (Escherichia coli, Salmonella, Pseudomonas fluorescens, Pseudomonas aeruginosa VTCC-B-657, Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Streptococcus feacium). The results indicated that perilla essential oil had anti-bacterial effects against all the above bacterial strains, except P. aeruginosa. The effect of perilla essential oil on gram-positive bacteria was stronger than that on gram-negative bacteria. The pure essential oil completely inhibited four strains of gram-positive bacteria, including Bacillus cereus, Bacillus subtilis, Staphylococcus aureus and Streptococcus feacium, and one strain of gram-negative bacteria, namely P. fluorescens. The Minimum Inhibitory Concentration (MIC) was more than 8192 µg/ml for both Escherichia coli and Salmonella and from 1024 µg/ml to 4096 µg/ml for the other five studied strains.

Fishery economy is one of the key economic sectors of Hai Phong city that contributes about over 2.3% share to the city’s GDP and provides about 2,000 employment positions per year on average in the 2005-2012 period. In 2012, seafood exports from Haiphong reached USD 36.5 million, a positive contribution to the city’s overall economic growth. However, most fishermen in the coastal areas of Hai Phong city are still considered as a difficult and socially disadvantaged target group. The issues such as the depletion of marine resources, especially coastal resources, Eastsea conflicts, competition for fishing area and others have a great impact on fishermen’s livelihoods. Although there are many guidelines and policies on the development of marine fishery and support for fishermen, the results are still limited. Based on the theory of livelihood, some issues related to the life, and the employment of fishermen in Haiphong, this paper focused on analysis and evaluation to clarify the status of fishermen’s livelihood resources (human, natural, physical, social and financial resources), the impact of vulnerable environment to fishermen’s livelihoods, and the implementation of fishery development and fishermen support policies of Hai Phong City in the past period, thereby recommending solutions to help fishermen improve their livelihoods, generate employment stability, increase their incomes and minimize risks and damages caused by the vulnerable environment.

This study was conducted by surveying a sample of 255 vegetable buyers at 4 wholesale markets, 7 retail markets and 6 supermarkets in Hanoi city to examine their characteristics and behavior. The findings indicated that: 75.3% of vegegetable buyers are female. Important selection criteria are the freshness and color of vegetables. Some buyers often decide to buy vegetables at supermarkets because they trust on product traceability and trademark. Besides, others select to buy vegetables at markets because they are motivated by reasonable prices. In general, consumers trust on the quality of vegetables sold at supermarkets more than those sold at markets. They are willing to pay with higher price level if the vegetable quality is guaranteed. There are few differences in the convenience of purchasing vegetables at markets and supermarkets. To better meet consumers’ demand for vegetables, following measures should be taken: 1) Supporting for producers, collectors and wholesalers in understanding the need of consumers and, especially, the information about their choice; 2) Supermarkets should continue to sell certified products with specific trademark such as safe vegetables, VietGAP vegetables, organic vegetables to gian consumer trust, 3) State management agencies continue to improve the market planning and regularly control the food safety and sanitation and products’ trademark; 4) Producers should diversify products and apply safe vegetable production techniques and register the trademark and traceability for all of their products.

Leveling network adjustment program is built to process leveling network based on the principle of least square adjustment and allows to calculate quickly and accurately the number of network together with added new points and elevation differences. This program can be used for production tasks as well as teaching at universities or academies of Vietnam.