This study was conducted to determine the combined effects of flow rate and light intensity on the growth and survival rate of juvenile clam Lutraria rhynchaena. Clams were stocked at 3 clams/ sandy bottle and 40 bottles was laid in 200L PVC tank. Two factorial experiment was set up with 3 replicates per each treatment as follow: NT1-tank without cover, only supply aeration and water flow inside (stagnent condition); NT2-tank with net cover and stagnent condition; NT3-tank with thick PVC cover and stagnent condition; NT4-tank without cover, supply aeration and  water flow rate at 160L/h (running condition); NT5-tank with net cover and running condition; NT6-tank with thick PVC cover and running condition. Clams were fed twice a day with Chlorella algae from Tilapia-green water system and Chaetoceros algae at the density of 20000 cells/ml. After 60 days of experiment,  weight of clams reached highest in NT1 (0.66g) and lowest in NT3 (0.50g). The highest survival rate of clams presented in NT5 (85.0%) and the lowest value in NT6 (70.5%), however, there was not significant different among treatments (p>0.05).

The objective of this study was determined some factors that influenced to texture properties and storage time of surimi crab sticks from ?Tra? fish by-product (Pangasius Hypophthalmus). The impact of modified starch and additives, including PDP (chitofood, Poly-B - (1-4) - D-glucosamine), gluten, egg white to the structural characteristics as well as the effect of cooking time to product quality and safety were carried out. The results showed that surimi crab sticks obtained high sensory quality, high water holding capacity (WHC) and good texture in addition of 5% denaturated starch combined with 10% egg white or 0,35% PDP as well as 3% gluten. Cooking process at 80°C in 75 minutes were the best condition for surimi crab sticks production. The quality of product still keep stable during 12 weeks at -18 ± 2°C.

Tiger shrimp farming is one of the important economic sectors of Ben Tre and Soc Trang provinces. This study aims to assess the technical and financial efficiency as well as  linkages or collaboration of different intensive shrimp (Penaeus monodon) farming models in order to contribute to solutions for sustainable shrimp culure in the region. The study was carried out from September 2010 to May 2011 with four typical models, consisting of (i) Household shrimp farms, (ii) Farm enterprenuers, (iii) Cooperative/ group production/clubs, and (iv) Companies. The secondary information was collected from state organizations. Primary data was colleted though interviewing 100 shrimp farming units, including household shrimp farmers (60), farming enterprenuers (11), cooperative/group production/clubs (18), and shrimp farming commpanies (11). The results showed that the average yield and profit of each farming model was 5,336 kg/ha/crop and 244,246 thousand VND/ha/crop; 6,773 kg/ha/crop and 442,678 thousand VND/ha/crop; 6,450 kg/ha/crop and 317,783 thousand VND/ha/crop; and 8,355 kg/ha/crop and 553,118 thousand VND/ha/crop, respectively. The linkages and collaboration in farming shrimp are also discussed in details.

The study aimed at investigating the effects of supplying compost at different rates on soil physico-chemical properties. The experimental site located in the moutainous area in Tri Ton district, An Giang province, where Gac (Momordica Cochinchinensis (lour) Spreng) is recommeded to grow for pharmaceutical purposes. Soil was high in sand content and classified as Haplic Acrisols. Organic matter was supplied as sugar cane filter cake compost at rates of 0, 5 and 10 kg per plant. The field experiment was in completely block design and there were four replicates for each treatment. The amounts of inorganic fertilizers supplied were 50 g N, 60 g P2O5 and 120 g K2O per plant. The results indicated that applying compost improved soil available phosphorus significantly (p < 0.05). The contents of exchangeable Ca2+, Mg2+ and base saturation in soil were remarkedly increased when applying 5 and 10 kg compost per plant. Applying compost also resulted in an improvement in soil structural quotient (p < 0,05).

A study was conducted in Department of Aquatic nutrition and products processing,CollegeofAquacultureand Fishries from January to May of 2011. The study consisted of two experiments. The first experiment was determination of sensibility of Cholinesterase (ChE) on common carp exposed to quinalphos at different concentrations. The treatments were 0, 0.0076, 0.076, 0.152, 0.380 and  0.57 mg/L, 3 replicates for each concentration, 30 fish per 100 L-composite, and for 96 hrs. The brain ChE activity significantly decreased after 96 hrs. at tested concentrations if compared to control. ChE activity had no signal of recovery after 96 hrs. The second experiment was determination of physiological parameters of common carp in conditions of direct exposure to quinalphos and contaminating in 24 hrs. before experimental design. The treatments were 0, 0.076, 0.152, 0.380 and  0.57 mg/L, 6 replicates for each concentration, 2  fish per 2  L-glass pot (oxygen consumption experiment) and 4 fish per 2 L-glass pot (oxygen threshold experiment). The results indicated that oxygen consumption and threshold significantly increased (p0.05). Meanwhile, oxygen threshold had a tendency to increase significantly (p

The research was conducted to identify specific land use systems in the Eastern ? coast of the Vietnamese Mekong Delta. In addition, the possible impacts of projected climate change and sea level rise on agriculture and aquaculture was evaluated and the possibility of land use changes was also analyzed. Such analyses were done for the historical context (1960 ? 1999) and projected climate change and sea rise in the future (2050). The specific land use systems in Vinh Chau district included shrimp system, vegetable system, the rotation of rice and vegetable, salt ? artemia and shrimp ? rice ? vegetable. The natural and social ? economic factors and possible causes of changes in such the existing land use systems were also analyzed. The study presented the water cycle characteristics within the household; this is important to determine the status of water use and the ability to optimize water use in the future. Simulated data of SEA ? START showed the temperature in the study area would raise while the rainfall (over the whole year) would fail from 2011 to 2050; the hydrological change after the project sea level rise would be considered as the main causes leading to the large proportion the study area would be intruded by sea - water (with high concentration of above 25 g/l).

Study on some haematological and biochemical parameters relating to reproductive characteristics of mullet (Liza subviridis) in mature period were conducted at College of Aquaculture and Fisheries, Can Tho University in oder to find out the correlation of gonadal with some haematological and biochemical characteristics of mullet. Studies on haematological and biochemical indices relating to maturation of fish were conducted with 174 fish (14.2 ? 23.3 cm; 43.4 ? 225.3 g). Results indicated that when ovary of fish developed from stage II to stage IV, number of red blood cells decreased while the cell volume increased; vitellogenin content increased and reached the highest level at ovary stage III. Protein content in plasma and liver, in contrast, decreased with the development of the ovary. However, other indices such as hemoglobin, MCHC, protein content in muscle of female fish, as well as white blood cell counts, vitellogenin content, protein levels in liver and muscle of male fish did not significantly relate to developing stages of ovary or testis.

This study was carried-out from August, 2011 to May, 2012 in Tra Vinh Province. The study focused on the morphology, growth and reproductive biology of Squirrelheaded catfish (Arius sciurus). Samples (30 - 40 fishes each time) were collected monthly. The results indicated that Squirrelheaded catfish belongs to the order Siluriformes and largely distributes in freshwater and brackishwater. There was a high correlation between length and weight in the regressive equation, W = 0.01L2.9639 with R2 = 0.9622. The von Bertalanffy growth parameters (maximum length L , growth coefficient K and the age of zero length t0) of Squirrelheaded catfish were L = 20.65 cm, K = 0.98/year, t = -0.83 year. Maturaltion of Squirrelheaded catfish showed that the highest values of GSI (5.74%) was observed in December and the lowest one (1.12 %) in August. The fecundity ranged from 461? 1,047 eggs/female fish and the relative fecundity from 11,813?16,362 eggs/kg of female fish.

This study aims to evaluate the impacts of meteo-hydrological (temperature and rainfall) changes on rice yield in the semi-dyke protected area in An Giang province by CropWat model. The CropWat model the reliability of SEA START data. Climate change data in the future (2030s) were bias-corrected using monthly delta change method (A2 and B2). ). This data were then input into was calibrated and validated (2003-2007) to simulate rice yield. The meteo-hydrological data simulated by SEA START were compared with observed data for a period of 27 years (1981-2007) to check the calibrated CropWat model to assess the impacts of temperature and rainfall changes on rice yield under three developed scenarios. The results showed that bias between observed and simulated data (temperature and rainfall) was acceptable (3.0oC and 9.6%, respectively). For scenarios A2 and B2, in the 2030s, temperature will increase (1.8oC and 2.0oC, respectively) while rainfall will decrease (8.0% and 8.4%, respectively). Impacts of temperature and rainfall changes on rice yield under three developed scenarios are found to be insignificant. When temperature increases or/and rainfall decreases, rice yield will decrease (but the impacts on the DX and HT seasons are different). However, besides temperature and rainfall, the impacts from other factors such as humidity, sunshine hours and wind speed on rice yield should be considered in the further research.

Xa-kê (Artocarpus altilis (Park.) Fosb.) ở Việt Nam được biết đến như một loài cây trồng phổ biến với rất nhiều công dụng làm cảnh hay trị bệnh. Theo Zerega et al. (2004, 2005), tên gọi ?Xa-kê? được sử dụng để chỉ loài Artocarpus altilis (Parkinson) Fosberg, nhưng đôi khi tên gọi này cũng được dùng khi nói đến Artocarpus camansi hoặc Artpcarpus mariannensis. Nghiên cứu đã dùng phương pháp so sánh hình thái và phương pháp giải phẫu cấu trúc mô để phân loại các mẫu Xa-kê thu tại Tiền Giang, Cần Thơ, và TP. Hồ Chí Minh. Kết quả cho thấy các cây Xa-kê chia thành hai nhóm hình thái có thể phân biệt là Artocarpus altilis và Artocarpus camansi. Giải phẫu mô của các cây trên cũng cho thấy những cấu trúc rất đặc sắc của nhóm cây này.

For the purpose of improving the quality, peel color and prolonging the preservation of ?Đường? mandarin, some single and combined chemicals (including gibberellic acid, calcium chloride and ethephon) as postharvesrt treatments were used. The chemical treatments were sprayed on fruits at 1 week (ethephon) and 1 month (calcium chloride and gibberellic acid) before harvest. The research results showed that all chemical treatments could reduce the percentage of weight loss and maintained the peel color, the pH level as well as Brix ratio stably. Spraying 2.000 ppm calcium chloride alone or combined with 100 ppm ethephon could improve the peel color better. The shelf life of some treatments including 20 ppm gibberellic acid alone, 20 ppm gibberellic acid combined with 2.000 ppm calcium chloride or 100 ppm Ethephon was achieved up to 5 weeks with the stable level of ascorbic acid content.

An on-farm feeding experiment was conducted to determine the effects of catfish by-product meal (BCT) replacement at 0, 50 and 100% of sea fish meal (BCB) with probiotic (M) supplementation in the diets for Luong Phuong chicken. 240 chickens at 3 weeks of age were allocated into four householders with 3 treatments/householder. Sixty chickens/householder were designated in 3 treatments (BCT0, BCT50, BCT100) used for 10 weeks then slaughter to evaluate the meat quality. Weight gain, feed intake and feed conversion ratio were non significant differences for bird fed diets with various levels of BCT, except cost/kg gain was reduced when increasing BCT in the diets. There were no significant differences among carcass weight, thigh and breast percentages. However, there were higher (P

The MODIS data with high temporal resolution provided by NASA is available in global coverage, enables to research fluctuation of land surface temperature with multi-temporal and multispectral data. In this research, we used MOD11A2 (1-km spatial resolutions, 8-day composite) from 2000 to 2010 for initially calculating and assessing fluctuation of Land surface temperature (LST), Temperature/Vegetation Dryness Index (TVDI) inMekongRiverdelta combining agricultural household interview in the study area. The research has developed a completed process for calculating the Land surface temperature and Temperature/Vegetation Dryness Index for theMekongDelta by using MODIS images. The executed temperature data from this process has high reliability by means of high correlation with the measured data from meteorological stations. In addition, the areas with high TVDI corresponded with field survey of current land use at the same time. These results show that applications of Moderate Resolution Imaging Spectroradiometer (MODIS) with low spatial resolution (1km) and high temporal resolution (8 days) to monitor and forecast drought ofMekongDelta is appropriate. The results will contribute a new approach to resolve the determination of drought related to climate change at present.

The objectives of this study were to select the Gac variety which has high fruit yield and lycopene content for medicine production. Experiment was executed with three Gac varieties growing on alluvial soil Eutric-Haplic-Gleysol in experimental area of Can Tho University. Results showed that three Gac varieties had a period of fruit development of 82-109days. Fruit weight was in a range of 1.08?1.46 kg and fruit yield of 7.8?12.5 tons.ha-1. OMC variety had highest fruit yield. Beta-carotene content was 133,3?764,3 ?g.g-1 fresh meat fruit, OMX variety had highest ?-carotene  content, 764,3 ?g.g-1 while  lycopene content of three varieties was about the same, 840?1223 ?g.g-1. OMC variety which had highest fruit yield and relative high lycopene content, can be selected for cultivation in large area for medicine product. OMX variety which had high  ?-carotene  content can be a good variety for a product related to ?-carotene.

This study was conducted to evaluate the reuse ability of bottom sediment from intensive catfish ponds to produce organic fertilizers and their application in rice cultivation. The bottom sediment was mixed with inorganic fertilizers to form mineral organic fertilizer  2-1-2, and folia feeding fertilizer 6-6-3; corresponding with a mixing ratio of N, P2O5 and K2O. The study consists of 3 treatments: NT1: 80-70-30 kg NPK.ha-1; NT2: 54-2-4 kg NPK.ha-1 (200 kg mineral organic fertilizer 2-1-2 + 50-0-0 kg NPK.ha-1 + folia feeding fertilizer 6-6-3); NT3: 124-62-34 kg NPK.ha-1 (200 kg mineral organic fertilizer 2-1-2 + 120-60-30 kg NPK.ha-1). The results showed that, there were no significant difference in growth and components of rice yield such as number of panicles per square meter, number of grains per panicle, filled grain ratio, and 1000 grain weight among treatments (p> 0.05) after 70 days. However, rice yield in NT2 and NT3 showed significantly lower than that of NT1 (only inorganic fertilizer) (ưp< 0.05). For the quality parameters of rice, there were no significant differences in heavy metals and amylose concentration among treatments (p> 0.05). Amylose concentration in rice varied from 18 to18.6%. In treatment NT2, use of organic fertilizers could reduce 2.5 million VND ha-1 from the cost of rice production. It is therefore concluded that bottom sediment from intensive catfish ponds can be utilized to produce the organic fertilizers and further research is imperatively needed to evaluate their effectiveness on other plants.

Đề tài được thực hiện nhằm tìm ra các điều kiện nuôi cấy Aspergillus niger PE1 như pH, ẩm độ, thời gian, khoáng chất cũng như nguồn cơ chất thích hợp để tăng năng suất sinh tổng hợp phytase. Đồng thời khảo sát một số điều kiện lý hóa để ứng dụng enzyme này vào trong chăn nuôi một cách hiệu quả. Kết quả nghiên cứu cho thấy với nguồn cơ chất là bột bắp thì chủng nấm A. niger PE1 sẽ cho hoạt tính cao nhất (8.897 U/g cơ chất) trong thời gian nuôi cấy là 5 ngày. pH tối ưu để nấm phát triển và tổng hợp enzyme là 7 cùng với ẩm độ là 60%, glucose pha trộn với sucrose (tỷ lệ 1:1) với nồng độ 1%, hỗn hợp malt extract và amonium sulfate (tỷ lệ 1:1) với nồng độ 0,25%, KH2PO4 1%. pH và nhiệt độ tối ưu cho hoạt động của phytase lần lượt là 3,5 và 65oC. Phytase khá bền ở nhiệt độ 4oC và pH 3,5 trong 24 giờ. Ngoài ra, phytase còn bị ức chế bởi một số ion kim loại như Fe2+, Mg2+, Mn2+, Na+, K+ và Zn2+ ở nồng độ 1mM và 5mM. Sản phẩm phytase thô kết tủa bằng acetone có thể được bảo quản ở dạng dung dịch ở pH 3,5 trong 3 tuần ở 4oC.

The aim of this research was investigated the optimum concentrations of plant growth regulators (BA, NAA, IBA) for shoot establishment, shoot multiplication and rooting of Ochna integerrima in vitro. The results showed that a) initial stage, the sterilized shoot tip or nodal explants were cultured on the MS medium supplemented with BA (4 mg/l) gave the optimum of shoot formation; b) rooting stage on 1/2 MS medium supplenmented with NAA (6 mg/l) formed more and normal roots.

A field experiment was conducted to evaluate effect of microbial-compost on hybrid-corn (Zea mays L.) growth and yield cultivated on an alluvial soil of Song Hau farm, Co Do district - Can Tho city from August 2011 to February, 2012. The results showed that using microbial-compost producing from sedimentation of intensive tra-fish bottom ponds and mixture of four strains nitrogen-fixing Azospirillum lipoferum and Burkholderia vietnamiensis, phosphate-solubilizing Pseudomonas stutzeri and potassium-solubilizing Bacillus subtilis saved up from 50% chemical fetilizer for hybrid-corn cultivation (90kg N, 50kg P2O5, 30kg K2O/ha) however yield did not differ from using 100% chemical fetilizer treatment; application of microbial-compost not only saved 50% chemical fertilizer level, reduced cost, enhanced income but also limited environmental pollution and soil fertility improvement.

Alcohol made of rice or glutinous rice are very popular in Vietnam. The aerobic- and anaerobic fermentation was followed as a model of study. As results, optimal fermentation durations were obtained for both steps. The contents of different volatile compounds including acetaldehyde, methanol, ester, total acid, isobutanol, isopentanol and furfural present in the final products were determined, giving a good relation between the materials used and the product quality. During the distillation processes, the presence of the aforementioned volatile compounds in differently condensed fractions was also investigated showing a good picture helpful for practically handling of distillation process.

In order to provide glutinous rice varieties with high quality, diversed types and suitable to different production areas, so the stable and adaptive criteria of MTL glutinous rice varieties were examined by analysising on interaction between genotypes type and environments. Experiments with RCBD in five sites of Can Tho, An Giang, Long An, Soc Trang and Tien Giang were conducted. Experimental data were collected by IRRI method (1996) and followed by analytical method of Eberhart and Russel (1996). Results showed that MTL677 glutinous rice was stable and adaptive with in two seasons a year. Glutinous rice varieties of MTL669, MTL672, MTL673, MTL680, MTL681 were suitable grown in Winter ? Spring season in almost glutinous rice production areas in theMekongDelta.    

Phalaenopsis sp., one of beautiful flower species of Orchid family, is cultivated for cutting and decorating in houses. Chitosan, which was extracted from the cell walls of crustacean exoskeletons, was reported as an efficient substance for the plant growth including orchids. Objectives of this study were to determine effects of chiosan at different concentrations on growth of in vitro Phalaenopsis shoot clumps and plantlets. Results obtained showed that the complement of chitosan 5-25 mg/l was effective for the growth of shoot clumps, which obtained number of shoots, relative increasing height and ratio of root formation at high values. As regards plantlet culture, the concentrations of chitosan 15 mg/l and 25 mg/l improved considerably height and new root formation of plantlets at 70 days after cultured.

The research results showed that the quality of surface water was polluted by organic matter. Particularly, the coliform parameters was drastically over Vietnamese Standards for surface water quality from 3 to 60 times; the concentrations of COD, TSS, N-NH4+, and N-NO2- exceeded from 1 to 4,5 times; DO value is lower than the Vietnamese Standards. There were 14 species that belong to six classes such as Polychaeta, Oligochaeta, Bivalvia, Amphipoda, Gastropoda and Insecta. The density and biomass of benthic invertebrates ranged from 20 to 370 individuals/m2 and from 0,756 to 11,275 g/m2 respectively. The ASPT biological index was in ranged of 2,5 - 4,75. It is indicated that in any position with the high organic matter in the sediment will have high od density and biomass of benthic invertebrates.

Phosphorus (P) and potassium (K) are two essential nutrients for plant growth but the biggest proportions of P and K in soil are insoluble rocks, minerals and deposits. However, many groups of bacteria in the nature are able to convert insoluble P and K form into soluble ones (P and K), especially those bacteria are capable of dissolving both P and K. The aim of study was isolation of bacteria dissolve P and K strains from weathering material of granite rock of Sap mountain, An Giang province, identify these bacteria by PCR technique. From 9 weathered material samples of granite rock of Sap mountain, An Giang province, twenty-six P- and K-solubilizing bacteria were isolated. Their colonies were round or irregular, white or pale yellow and their cell were rod shape or the short chain and nonmotile or motile. Band of approximately 1500bp were obtained from the amplification of 16srRNA gene from 26 isolates that were dentified by PCR technique with specific primers fD1 and rP. After 10 days of incubation in the liquid Aleksandrov medium, 18/26 isolates had phosphate and potassium dissolution capacity were higher than 10mg/l P2O5 and 25mg/l K2O (12/16 isolates). Four isolates had high phosphate and postassium dissolution capacity (>10mg/l P2O5 and >30mg/l K2O) effectively and they werse chosen to sequence, DNA sequence were compared with GenBank database of NCBI by BLAST N software. The results showed that NS3 isolate was similarity of 99% with JQ428828 Bacillus pumilus strain R71 and JQ320096 Bacillus altitudinis strain XjGEB-71; NS6 isolate was 97% similarity with JQ419715 Bacillus sp. strain L2276 and JN644556 Bacillus nealsoni strain BP11-4A; NS7 isolate was 97% similarity with EF690427 Brevibacillus formosus isolate M13-7, HM590701 Brevibacillus choshinensis strain MHN5D, NS12 isolate was 99% similarity with HQ670584 Acinetobacter soli strain AIMST-PV1.0 and 99% similarity with GQ258635 Acinetobacter soli strain SR2.

Phytic acid is a molecule composed of myo-inositol 1,2,3,4,5,6 hexakis dihydrogen phosphate (Ins P6), a major component of phosphorus (P) in the plant. In seeds of the plant, there are contain about 50-80% of total phosphorus (Lott, 1984). At pH of 7.3 to 7.4, the form of phytic acid were negatively charged ions and linked the mineral nutrition produced complex components with high indigestion. Moreover, phospho was presented with form of phytate or phytic, human and monogastric animals were not absorbed. This the reason was made environmental pollution. In this studied, five different rice varieties such as OM819, OM4900, OM3536, D4 and D8 were used to irradiate with gamma rays at five degrees of 10kr, 20, 30, 40 and 50kr to produce mutant lines with low levels of phytic acid. Results showed that, in radiation level at 10kr no lines rice were expressed low phytic acid. At the level of 20kr, there are three populations of OM819, OM4900 and OM3536 were appeared low phytic acid with 8 lines rice were expressed low phytic acid in grain. At the level of 30kr, the results showed that seven lines were presented low  phytic acid, these lines belong to four populations as OM819, OM4900, OM3536 and D4. At the level of 40kr radiation, four populations appeared five lines were expressed low phytic acid, of which three lines were expressed level 3 and two lines with level 4, respectively. At the level of  50kr, there is only one line was expressed level 3, this is OM819 population.

Currently, concerns about environmental issues are increasing considerably in every agricultural sector. To reduce the environmental impacts, the production of agricultural products should be evaluated for the environmental impacts from the production process. This research was conducted through survey data on the use of fertilizers, pesticides, and gasoline from 150 rice fields of farmers in districts of Chau Thanh (Soc Trang), Cai Lay (Tien Giang), Thoai Son (An Giang), and Phuoc Long (Bac Lieu). Method of life cycle assessment (LCA) was used to assess the environmental impacts and done by the SimaPro software. The results showed that to produce one kilogram of rice the global warming impact was 609.6 gCO2-eq., the acidification impact was 4.7 gSO2-eq., and the eutrophication impact was 47.9 gNO3-eq. The impact of global warming in the production of one kilogram of rice was largely due to CH4 emissions from rice soil (69.04%) and the use of nitrogen fertilizer (26.84%). The use of nitrogen fertilizer caused the most acidified (93.63%) and the land use caused the most eutrophicated (80.30%).

The suitable regenerating medium for 10-day old cotyledon of tomato was MS containing  0.5 mg/l BA, 0.5 mg/l kinetin, 0.1 mg/l IAA and 8.4 g/l agar. pH was adjusted  at 5.8.The lethal dose of kanamycin on cotyledonary segments (control) was 100 mg/l.The introduction of plasmid pCAMBIA 2301 ? Cry1Ab into Agrobacterium tumefaciens train  LBA 4404 and the presence of Cry1Ab gene were tested by PCR technique. The OD600nm = 1 and 100 àM acetosyringone resulted in the highest transient GUS activity (45.6 ± 5.1%) on transgenic cotyledonary fragments. The presence of Cry1Ab gene in 2-week old cotyledonary fragments and 3-month old transgenic tomato in vitro plants was evidenced by PCR.

Seasonal rice varieties have been mainly cultivated along the coastal areas of the Mekong Delta for long time. In recent years, due to climate change, the farmer have taken advangtage of sea water to raise shrimp, land became degraduation, thus rice couldn?t plant, epidemic disease on shrimp become popular. The aim of this research was to find out rice varieties tolerant to strong land soil salinity. The experiment was carried out to test the salt tolerance according to the method of IRRI, 1997, the were designed according to the split plot method, 5 treatments and 3 replicates with 3 is Lua Soi varieties, Mot Bui Hong and Nang Quot Bien, the sensitive control was IR29 and the tolerant control was ?Doc Phung?. Results evaluate the salt tolerance level 5 rice varieties saline test after 16 days, Doc Phung, Lua Soi, Nang Quot Bien salt tolerance at level 5 (medium resistance) at a salinity of 12,5 ?, just Mot Bui Hong able to salinity tolerance level 5 (medium resistance) in 10 ? salinity seed IR28 infection the level 9 (very infectious).

A study on Aerenchyma characteristics of some aquatic plants under polluted water conditions was carried out to explain the mechanisms of plant adaptation in flooding condition, evaluating and selecting aquatic plant species in water quality improvement. There were three treatments: (1) wastewater with Colocasia esculenta, (2) wastewater with Hymenachne acutigluma, (3) wastewater with Eichhoria crassipes. The wastewater used in this study was the domestic wastewater from the dormitory. The plant species was measured the ratio aerenchyma/area at the 1st and 60th day of the experiment. The result showed that in stem the ratio aerenchyma/area of Colocasia esculenta increased 15% and much higher than Eichhornia crassipes and Hymenachne acutigluma (10% and 5% respectively). In root, the ratio aerenchyma/area of Colocasia esculenta increased 7% while Hymenachne acutigluma had only 4%.

In natural conditions, taro is cultivated by tubers and breeding rarely appeares. Therefore, creating a new vảiety by radioactive mutation should be used. This study was carried out based on 3 experiments with two species of taro Caladium bicolor andColocasia esculenta: (1) Effect of NAA, BA, nutrient solutions on shoot regeneration and growth of regenerated shoots from callus; 2. Effect of gamma on shoot regeneration and growth of regenerated shoots; (3) Effect of coconut water on shoot regeneration and growth of regenerated shoots. Results showed that, (1) Caladium bicolor: medium MS supplemented with 1 mg/l BA and 0,1 mg/l NAA had the best shoots; Gamma ray treatment with 3 rates of 20, 40, and 60 Gy had different phenotypes after 150 days ex vitro. (2) Colocasia esculenta: medium MS supplemented with 1 mg/l BA and 0,1 mg/l NAA had the best shoots; medium MS supplemented with 100 ml/l coconut water was better for shoots; Gamma ray treatments at 15 and 20 Gy did not change phenotype by observation but changed genotype by SDS-PAGE protein analysis.

Twenty-eight isolates which were likely to develop on Burk?s medium were isolated on Aleksandrov medium in twenty weathering-rock samples from Cam Mountain, An Giang province. Among twenty-eight isolates, five isolates synthesized high amoniumincluding CA03 (11.459mg/l), CA04 (9.816mg/l), CA10 (6.390mg/l), CA18 (10.973 mg/l) and CA29 (15.398mg/l). Three bacterial isolates were chosen to sequence and compare with GenBank database of NCBI by BLAST N software. The results showed that CA10 isolate was 99% of the identity with AY117623.1 Rhizobium tropici PRF34, CA18 isolate was 99% of identity with JF496331.1 Bacillus subtilis A2-9 and CA29 isolate was 99% of identity with JN896359.1 Rhizobium multihospitium CC-13H. Evaluation of nitrogen fixing ability of mixture of three bacterial isolates on Allium fistulosum sp. and Basella alba L. The results showed that they supported on plant height, plant weight and biomass.

The objectives in this work were to investigate the capability of constructed wetlands designed with subsurface horizontal and vertical flow in treatment of close-recirculated intensive catfish tank culture water. In?uent (i.e. fish tank water) and e?uent samples of the treatment systems were collected once a week for eight weeks and determined various parameters relating to the water quality. The vertical flow wetlands (VF) had significant lower concentrations of NH4-N, TKN, PO4-P and TP in culture water compared to the horizontal flow (HF) wetlands. In addition, the former system improved oxygen condition in culture water. Regarding to nutrient balance estimation, the VF system could remove 74% N and 69% P from influent, while the HF system removed 86% N and 72% P. Remarkably, renewable water is no need during the experimental period while water quality remained within limit for normal fish growth. Further studies on performance of the treatment wetlands longer time and searching more appropriate plant for the VF system are needed.