Vol. 12 No. 8 (2014)

Pot experiments were carried out in the green house at the Faculty of Agronomy in 2012 summer and 2013 spring seasons under low nitrogen (N1), intermediate nitrogen (N2) and high nitrogen (N3) levels to investigate flag leaf photosynthesis of a newly developed line of rice with early maturity andthe check cultivar IR 24. The experiments were arranged in randomized complete block (RCB) with 4 replications. At the heading stage, 7, 14 and 21 days after heading (DAH), a pot from each treatment was randomly selected to measure photosynthetic rate. Grain yield and yield components, were determined at harvesting stage. The results showed that season and nitrogen level affected photosynthetic rate at allstages. A significant and positive correlation between percentage of filled spikelets,1000 grain weight of IL19-4-3-8 and phototsynthetic rate at heading stage and 7DAH in summer growing season. Grain filling percentage of IL19-4-3-8 closely related with photosynthetic rate at heading stage and 1000 grain weight associated more closely with photosynthetic rate at heading stage and 7DAH than that at 14 and 21DAH inspring growing season. Photosynthetic rate at heading stage and after heading stages had great contribution to grain filling percentage and  1000 grain weight of IR 24 in both seasons.

The study was conducted to examine the physiological characteristics associated with drought tolerance at tillering and heading stage of several local upland rice cultivars collected from Northwest region of Vietnam. The results indicated that photosynthetic rate (CER), transpiration rate (Tr), and SPAD index (an indicator related with leaf chlorophyll content) were lower in upland cultivars than that in check variety (cv. LC93-1 ) when exposed to drought at tillering and heading stages, whereas these values were higher in upland rice at recovery stages. Drought at tillering stage significantly reduced the number of panicles per plant while drought at flowering stage significantly reduced the percentage of filled grains in the upland rice cultivars, consequently caused significant reduction in the individual grain yields. The photosynthetic rate positively correlated with transpiration rate during drought in both tillering stage and heading stage. A positive correlation was also found between the CER and SPAD index prior to drought treatment but it was not significant at drought and recovery stages. The individual grain yield was positively correlated with the CER at recovery stage. Four cultivars, Khau van lon, Nep nuong tron, Thoc gie and Te đo showed good recovery after drought treatment as well as higher individual grain yied, which might have better drought tolerance.

Development of maize varieties with high yield, good quality and tolerance to abiotic stresses, such as drought  and cold, and disease resistance will increase yield stability under adverse climatic conditions. Four experiments were conducted in 2013 autumn-ưinter season at the Institute for Crop research and development to evaluate 15 hybrid combinations and 6 inbred lines developed from local populations for drought tolerance in pots at seedling stage, to evaluate these materials under water stress condition in greenhouse and watered field condition, and to identify QTLs controlling yield under drought conditions and drought index of six inbred lines and 15 maize hybrid combinations. The results obtained from greenhouse and field experiments have identified 3 inbred lines lines and 7 hybrid combinations with high drought tolerance. These are D4, D5, D6, THL4, THL6, THL7, THL9, THL10, THL14, THL15. SSR molecular markers (umc1862, umc2359 and nc133) were able to identify QTLs controlling both Ys and TOL traits in the same materials. Therefore, 7 maize hybrid combinations and 3 inbred lines (THL4, THL6, THL7, THL9, THL10, THL14 and THL15 and, D4, D5, D6, respectively) were selected for drought tolerance.

Over the last years, the demand for good quality of milled/white rice in the Red River Delta (RRD) of Vietnam has been increasing rapidly. To meet that demand, breeding new varieties with fine grain quality, suitable for cultivation conditions and climate of the RRD is of crucial significance and a prerequisite. Identifying criteria for breeding good quality rice can help rice breeders to keep breeding programs on track. From the results of investigating consumer preferences and the consumption of good quality rice in the market as well as evaluating agronomic characteristics and milled rice of quality varieties accepted by market, selection criteria for quality varieties for the RRD were established. The main criteria include early maturity, stable yield (5.5-7.0 tons/ha), low to moderate amylose content (17-23%) and fragrance. However, there were no strict requirements for grain length and grain shape and the breeders can select varieties that have long, medium or short grain.

Recently, the bulb mite, Rhizoglyphus echinopus became an important pest attacking bulb corms and tubers of a variety of crops and ornamentals in greenhouse and field conditions. A study was carried out to investigate the effect of temperature on population growth of this mite species. Onion slides were tested as a nourishement of Rhizoglyphus echinopus at varying room temperatures, 200C, 250C and 300C but at constant relative humidity (RH) of 95%. The results showed that temperature significantly affects the life cycle, hatching rate of eggs, survival rates of all stages and population growth rates of the bulb mite. Life cycle of Rhizoglyphus echinopus was shortest at 300C (8.48 days), but longest at 20oC (14.29 days). The intrinsic rates of natural increase of the bulb mites at 200C, 250C and 300C were 0.20, 0.26 and 0.29, respectively. This showed that the bulb mite has a high population growth rate.

 Eighteen newly developed inbred rice genotypes were evaluated with the emphasis on important agronomic traits, namely pollen restoring ability, reaction to major pests and diseases, and yield and yield componenents. Pureline selection design was set up including R50 cultivar as a male parent check. Seven promising inbred lines were selected, viz. 46-1, 46-2, 76-3, 76-4, 78-1, 81, and 82-2. They were used as restorers to hybridize with TGMS lines,l 103s and 135s. The evaluation of F1 combinations indicated that 135s /76-4 is promising showing early maturity and high yielding.

Pot experiments were carried out in the green house at Faculty of Agronomy in 2012 autumn and 2013 spring seasons under low nitrogen (N1), intermediate nitrogen (N2) and high nitrogen (N3) ratesto evaluatethe accumulation ofnon-strutural carbohydrates(NSCs)in stems of a newly developed line with early maturityand the check cultivar IR 24. The experiments were laid out in randomized complete block (RCB) with 4 replications. At the heading stage, 7, 14 and 21 days after heading (DAH) one plant of each treatment were randomly selected to measure leaf area, dry weight of stems and total mass of non-structural carbohydrates (TNSCs) translocated from stems to panicles. Grain yield was determined at harvest. The results showed thatnitrogen levels affected NSCs accumulation in stems at heading stage and TNSCstranslocation. The contribution of NCSsin stems at heading stage to grain yield was higher in IL19-4-3-8 than in IR 24. The amount (mg/g) of NSC residues in stem at after heading stage of IL19-4-3-8 was lower than IR 24. Sinigficant and positive correlation was found betweenTNSCs from heading stage to 7 day after heading (DAH) and individual grain yield of IL19-4-3-8 in both season, whereas the correlation was positive but insignificant in IR 24.

A study was carried out at households of Cho Moi district, Bac Kan town, Bac Kan provine from 2009 to 2013 to evaluate carcass performance and meat quality of Co goats; crossbred F1(Boer x BachThao) x Co and crossbred F2(3/4 Boer 1/4 BachThao) x Co. Results showed that their dressing and lean meat percentages of crossbred were higher than Co goat, goats (3/8 Boer, 1/8Bachthao and 1/2 Co) was 45.80% and 36.07%, respectively and goats (1/4Boer 1/4BachThao 1/2Co) was 45.17% and 35.36%, respectively, while the figures of Co goatwas 42.33 and 31.72%, respectively. Crude protein content of Co goat was higher than goats (3/8Boer 1/8BachThao 1/2Co) and goats (1/4Boer x 1/4BachThao 1/2Co). Cholesterol content in meat of goats (3/8Boer 1/8BachThao 1/2Co) and goats (1/4Boer x 1/4BachThao 1/2Co) meat was lower than that of Co goat. It was, therefore, suggested (Boer x Bach Thao) goat be used as male to mate with Co goat to obtain high carcass performance and meat quality. The levels of essential amino acids of Co goat meat was higher than goats with 3/8Boer 1/8Bachthao 1/2Co) and (1/4Boer 1/4BachThao 1/2Co). Although body weight of Co goats was smaller, but the nutritional value of Co goat meat was high.

A formal survey was conducted to examine the status of agricultural land area transfored to industrial land in My Hao district, Hung Yen province, and the land use efficiency in the remaining agricultural land and to recommend solutions to improve agricultural land use efficiency. In the 2005-2012 period, industrial land increased by 280.12 ha, in which 235.68 ha was converted from agricultural land. Decreased agriculture land has created high pressure on the use of agricultural land resource and caused change in land use types (LUT). In 2005, the district had five LUTs with fifteen cropping patterns, however, there were 21 cropping patterns in 2012. The change in the area of land use types brought land use efficiency with it. Increased the land area was mainly attributed to fruit cultivation and VAC system. The land use efficiency of the LUTs increased in 2012 in comparison with 2005. Highest economic efficiency was obtained from aquaculture and lowest economic efficiency from 2 rice croppings.

Tien Lang is located in the south Hai Phong city and situated in the southern coastal area It is a purely agricultural district with 68.92% of land grown with rice. During the last years the rice growing area decreased significantly. The government authority and communities gave priority to shifting agricultural structure to adapt to climate change. An interview was carried out on 300 representative households in the district representing different types of land use. The study revealed that crops and livestock of higher economic efficiency (pipe tobacco, potato, onion, tomato, melon, pepper and aquaculture) are well adapted to climatic change. Although the area under these crops is of low proportion (23.31%) in the cropping structure but it has become concentrated. These plants and aquaculture have high potential and prospects for high added value and production value could reach from VND 150 to 1,296 million/ha. In future, the district needs tight control of rice land changes, giving priority to expanding the area of economic crops such as rice cv. M6, potato, pipe tobacco and aquaculture to enhance the economic efficiency in response to climate changes.

The research was carried out on the barberry plants to evaluate the root mass production by aeroponic technology in comparison with traditional cultivation method. The results showed that the barberry root mass produced after 1 year in the aeroponic system was 3.43 times higher than that produced by traditional methods of cultivation. In the aeroponic system, the barberry plants thrived well when nutrient levels were set at 1300 to1600 µs/cm with the interval of 10 seconds spraying and 15 seconds pause. The findings are of great significance, serving as basis for bio mass production of the precious medicinal plants using aeroponic technology.

Colchicine has been successfully used for in vitro treatment for inducton of polyploids in many plants with high efficiency. The aim of this study was to generate new polyploid lines of China pink for breeding and selection in Vietnam. The experiments were carried out on the cultivar Tim Vien Trang of China pink (Dianthus chinensis). In vitro nodal stems were used for treatment with colchicine solution atconcentration of 0, 0.01%, 0.05% and 0.1%  for 24 hours, 48 hours and 72 hours. The mutant types were isolated based on morphological characteristics in in vitro and in vivo conditions. The results showed that the ploidy mutation rate was in a range of 0.87% to 12.85% when the explants were treated in 0.05% and 0.1% of colchicine solution for 24 hours and 48 hours and in 0.01% and 0.05% of colchicine solution for 72 hours. The mutants had highest quality from the treatments of 0.05% and 0.1% of colchicine concentration for 48 hours. Among eight different mutant types, the mutant types D7 and D9 carried several superior morphosological features such as the plant height, leaf size, flower diameter, flower longevity and color intensity in comparison with original cultivar. These two polyploid lines were cloned in vitro for further evaluation of genetic stability.

This paper introduces the principal selection of the structure of the slanting-cutting-planter part in the cassava cutting cutter-planter conjugation machine. The results showed the calculated soil compressed pressure under safe conditions for cassava cuttings after planting and factors affecting inclination angle of the cassava cuttings after planting. In case of the compressed pressure [σ] that secured the cassava cuttings was less than or equal to 2,99 N/cm2, factors which affected the inclination angle of the cassava cuttings after planting included forward speed (Vm) of the conjunction machine, the time (t) counting from starting placing the cassava cutting into the soil to finish soil compressing, the length (l) of the cassava cuttings, the C’D’ length which depended on b inclinable angle of the cutting path-trough (the bigger b angle was, the smaller C’D’ length was). If values of Vm, t, C’D’ length and l were given in advance, we would figure inclination angle of the cassava cuttings after planting. The calculated results were in agrement ưith the tested results. 

This study presented the results of late blight resistance and agronomical traits of backcross (BC) hybrids between the somatic hybrids and cultivated potato varieties as the pollen donor. The BC1 hybrids were grown and systematically evaluated for late bright resistance using artificial inoculation on seedlings (seedling test), on single detached leaves (detached leaflet assay), and on the tuber slices (tuber slice test). The presence of resistant gene Rpi-blb1 was also verified by molecular markers in the BC1 progeny. The results revealed that four BC1 hybrids of blb2G (+) with Delikat possess high resistance to late blight. Molecular analysis using two specific primers (blb1 and 1/1') of resistant gene Rpi-blb1 detected that the wild type S. bulbocastanum; the 2283/5 somatic hybrids of the blb2G (+) Delikat hybrid combination and the BC1 progenies contained this resistance gene. In addition, the BC1 hybrids also carried several desirable agronomical characteristics of cultivated potatoes. This study confirmed that protoplast fusion was successful in transfering late blight resistance gene from the wild type potato to the somatic hybrids and the resistance was maintained in the BC1 progeny. The BC1 hybrids carried several desirable traits of cultivated potato cv. Delikat.

Planting mangrove trees on sandy soil poor in nutrients often encounters many difficulties such as slow growth of seedlings and low resistance to pests. The addition of useful microorganisms as nitrogen fixing and phosphate solubilizing microorganisms to soil will create better conditions for growth and development and increase the resistance for the seedlings. The studies on cultural conditions indicated that two phosphate solubilizing fungal strains, Aspergillus sp. M33 and Aspergillus sp. M72 produced highest biomass in the Czapek medium added with starch or saccharose and meat extract at pH=6, salinity 5-10‰ after 60-84 hours culture. Mangrove plants planted in pots containing soils innoculated with two phosphate solubilizing strains, Aspergillus sp. M33 and Aspergillus sp. M72 showed better growth in terms of the plant height and leaf number.

Phalaenopsis Sogo Yukidian is a beautiful, lovely and high value orchid in the world and also in Vietnam. An in vitro culture protocol for rapid propagation was established to multiply this valuable flower. Nodal buds of inflorescence of Phalaenopsis Sogo Yukidian were used as initial materials. Optimal sterilization treatment was obtained with CaOCl2 15% for 7 min and then with Presept (Johnson and Johnson) 1% for 3 min. The optimal medium for protocorm regeneration was MS + 2.0 mg/l BA + 6g/l agar. The optimal medium for shoot induction was MS + 0.5mg/l BA + 0.5mg/l α NAA + 6g/l agar. Shoots grew fastest on MS medium supplemented with 10% coconut water. MS medium supplemented with 10% coconut water + 3.0mg/l BA + 6g/l agar was the best medium for shoot multiplication with the multiplication rate of 4.20 times after 6 weeks. MS medium supplemented with 10% coconut water + 0.5 g/l activate charcoal + 6g/l agar was the suitable for rooting.

 Dendrobium officinale Kimura et Migo. is a precious orchid and has been using as medicinal plant. Moreever, this plant has been used to produce functional foods for treatment of diabetes and difficult-to-cure diseases, which are commercially available world-wide. In vitro propagation of D. officinale Kimura et Migo was conducted in order to maintain the genetic pool of this precious orchid species. The results showed that the medium for in vitro seed germination was VW + 10g sucrose + 6g agar + 100ml coconut milk per liter. The best medium for rapid propagation of shoot cluster was MS + 20g sucrose + 100ml coconut milk + 6g agar + 0.5 mg BA + 60g ripe banana per liter. The most appropriate medium for propagation of in vitro nodal stems was MS + 20g sucrose + 100ml coconut milk+ 0.5mg/l α-NAA + 6g agar per liter. The rooting medium was RE + 10g sucrose + 6g agar + 0.3g active charcoal + 0.5 mg/l α-NAA per liter.

The inappropriate use of antibiotics might cause  the development and wide spread of drug-resistance. Therefore, finding new antibiotics from marine microorganisms has been receiving attention by the scientists. This article presents the taxonomical characterization and antimicrobial  activity of marine actinomycet strain VD111 isolated from Vietnam’s seawater. Based on Bergey’s classification and method of International Streptomyces Project (ISP), the strain VD111 was classified as Streptomyces albogriseolus since it had biological characteristics similar to the standard strain Streptomyces albogriseolus ISP 5003. The favourable conditions for the growth of the strain VD111 were established; temperature of 370C, pH of 7-8 and NaCl of 7-10%. The suitable medium and fermentation conditions for producing antimicrobial substances by the strain VD111 were A4H medium with the following substances expressed in g/l: 15g glucose, 15g soybean powder, 5g NaCl, and 1g CaCO3 and, pH=7. The preculture supplement was of 5.0% (v/v) and inoculum age of 48 hours. Maximal antibacterial compound yield (diameter of inhibition zone against Bacillus subtillis ATCC 6633: 30,2 mm) and biomass (10,6 mg/ml) were achieved after 60 hours of fermentation. Especially, the bioactive compound from strain Streptomyces albogriseolus VD111 exhibited antimicrobial activity against gram-positive, gram-negative bacteria and yeast (Candida albicans ATCC 10231).

The study was carried out to examine callus induction and plant regeneration of seven rice varieties, BM9630, NV1, NV2, NV3, and J02 (japonica group) and Huong com and BC15 (indica group). Percentage of callus formation of all varieties ranged from 72 to 98%, especially, the callus induction of Huong com, NV1 and J02 was above 90% (97%, 92% and 98%, respectively). The optimum callus induction medium for Huong com variety and other japonica varieties was N6 + vitamin B5 + 3 mg/l 2,4-D + 100 mg/l myo-inositol + 500 mg/l L-proline + 500 mg/l L-glutamin + 300 mg/l casein hydrolysate + 30 g/l sucrose.  Temperature significantly affected callus formation and its quality; the highest percentage of callus induction was obtained at 280C. Shoot regeneration from callus of Huong com, BC15, and J02 varieties on four media were obtained, however,  BC15 showed poor regeneration capacity on all types of media. High shoot regeneration of J02 and Huong com was obtained on N6 + vitamin B5 + 3 mg/l BAP + 1 mg/l α-NAA, 100 mg/l myo-inositol, 500 mg/l L-proline, 500 mg/l L-glutamin, 300 mg/l casein hydrolysate, 30 g/l sucrose.

Physical education is a compulsory content of the training program of Vietnam National University of Agriculture. The results of a baseline study at the university showed that physical education programs are in accordance with the conditions required by the university’s curriculum. However, there exist various constraints: namely limted students’ extracurricular activites, lack of faculty staff and staff qualification, and out-of date training facilities. Also, only few students participated in activities at the club sports and the students attained only averaged learning outcome/ performance in physical education subjects.The level of student fitness was moderate and the need for physical exercies are high. To solve these problems, five measures were proposed to improve the student learning outcomer in physical education courses. These are advocating the effect of sport, improving the course and program content, strengthening extracurricular activites, facility improvement and improved qualification of physical education teachers.

According to the decision No. 68/2005/QD-TTg, the trademark and collective trademark are of concern and support by the government. Based on survey data of 80 household farmers growing garlic and using contingent valuation method (CVM), the study clarified the status of garlic production  and analyzed effect of some factors on the needs for participation and using collective trademark (CT) of Thai Thuy garlic. The four main factors included gender, education level, income generated from garlic production and scale of garlic production. Income and the scale of garlic production were considered to have great effect on the need and willingness to pay (WTP) level for participation and using CT. From the survey, the research has also suggested measures to increase the level of participation and use of collective trademark for Thai Thuy garlic product.

Behaviors of farmer households in the northern mountainous region of Vietnam to chilling cold, bitting cold focus on maximum exploitation of households’ human resources and minimum expenses. In cultivation, farmer households mainly change planting seasons rather than variety and cropping systems. In animal husbandry, most of them reserve feed, shield and consolidate breeding facilities. They interindepend and help each other before, during and after bitting cold and chilling cold. Solutions to raise households’ ability to behave towards bitting cold and chilling cold aims at: Enhance inhabitants’ awareness of bitting cold and chilling cold; Support them to consolidate houses and cold - prevention tools; Train them ways to prevent cold on humans, crops and animals; Complete and boost natural disasters prediction and warning; Consolidate public constructions to be cold - prevention venues for people; Concentrate on building infrastructure adapting to bitting cold and chilling cold; Continue to complete policy mechanisms for bitting cold and chilling cold prevention.