Vol. 22 No. 4 (2024)

Dendrobium officinaleKimura etMigoof the genus Dendrobiumis a rare and endangered orchid species. In vitromicropropagation was carried out for preserving and developing this precious orchid genetic resource. All experiments were arranged in a randomized complete design (RCD) with three replicates. The results showed that the fruit as initial material source produced 100% survival of explants, generatingprotocorn and shoots and superior to the initial material source of using buds (rate of survived explants was only 2-3%).The addition of coconut water to the culture medium did not have a clear effect on the morphogenensis of Dendrobium officinale.The MS medium was the most suitable forrapid multiplication of orchid shoot clusters (2.56protocorn/8weeks). Adding growth regulator -NAAat a concentration of 1ppm or BAP at a concentration of 3ppm to the basal medium produced the largest number of shoots (45 protocorn/8weeks) and high shoot multiplication coefficient (2.61protocorn/8weeks). For in vitrogrowth of orchid shoots, RE mineralculture medium supplemented with 0.1% activated charcoal was optimal for plantlet regeneration.

Lettuce is high nutritional plant. Research was conducted to find the optimal LED light intensity for indoor hydroponic green oakleaf lettuce cultivation, contributing to ensuring the supply of safe vegetables for consumers and optimizing power consumption. The experiment was arranged in a randomized complete block design (RCBD) with three replicates. Evaluatingthe effects of four different light intensities (90-130-160-190µmol.m-2s-1 (under a combination of red, blue and green LEDs, spectral ratio: R660/B450/G550= 57/17/26) on growth, physiology and yield of hydroponic cultivated green oakleaf lettuce indoor was performed. The results showed plant height, leaf number, photosynthetic pigment content, leaf area, leaf thickness, root parameters, Brix and yield increased as light intensity increased. Among the lighting treatments, 190 µmol.m-2s-1 treatment had the best effect on the growth and yield of green oakleaf lettuce.

Pseudorabies has been known in Vietnam for a long time and is still one of the most devastating diseases of particular concern of animal breeders. Despite the emerging and prevailing of variants the virus in many countries around the world since 2010, to date, there is scarce information about the disease as well as the virus circulating in Vietnam. This study aimed to clarify some basic biological and molecular characteristics of an isolate, PRV.PT.001 strain. The isolated strain quickly adapted, induced typical syncytium on Vero cells and reached a relatively high titer after 7 passages (106.58TCID50/ml). The isolate had common characteristics of the virus that causes pseudorabies: it is pathogenic to rabbits and piglets, induces consistent lesions in the respiratory tract, and is widely distributed in many internal organs. Regarding genetic characteristics, strain PRV.PT.001 belongs to genotype 2, carrying typical insertion-deletion mutations in 3/4 of the investigated surface glycoproteins (gB, gC, gD ); but has the characteristic insertion-deletion mutation of genotype 1 in gE glycoprotein.

The study was conducted to evaluate antibody titers against IBDV and the productivity of commercial broiler flocks at field trial vaccinated with live vaccine Tabic MB and immune complex vaccine (IBDV-Icx). A total of 240 blood samples were randomly collected from 2 farms to test antibody titers against IBDV by ELISA technique. Mean body weight, average daily weight gain, and FCR were monitored until slaughter. The results showed that the chickens had high level of maternally derived antibodies (MDA). At 3 days old, the mean MDA was 5,582 titer units. At 30 days old, the number of positive samples with anti-IBDV (> 396 titers) in the group using Tabic MB and IBDV-Icx vaccines was 20% and 5%, respectively (P <0.05). Especially at 35 days of age, the titer at farm using the Tabic MB vaccine was 2,671 , which was significantly higher than that of the farm using the IBD-Icx vaccine, with titer of 132 only (P <0.05). Chicken body weight and average daily weight gain of this survey were similar (P >0.05). However, the FCR of chickens using Tabic MB vaccine was lower than chickens using IBDV-Icx vaccine (P <0.05). Briefly, commercial broiler chickens using Tabic MB vaccine had higher antibody titer against IBDV and productivity parameters were not affected compared with vaccinated with IBDV-Icx .

Showing amphibious features, mudskippers have been used as model species to gain understanding of the water-to-land transition of vertebrates. This study aimed to elucidate the relationship between terrestrial degrees and the utilization of pectoral fin-based locomotion and their morphology as well. The locomotor behavior, the aspect ratio of the fin, and the muscle ratio of three mudskippers and one goby were investigated. Results show that terrestrialization gradually increased in mudskippers, from Oxuderces nexipinnisto Scartelaos histophorusand Periophthalmodonseptemradiatus. Oxuderces nexipinnisand S. histophorusused the pectoral fins for crutching in aquatic, semi-aquatic, and terrestrial environments. They also employed the pectoral fins for waterskiing which is first reported for mudskippers in this study. In Pn. septemradiatus, the pectoral fins were mainly used for crutching on land (57.73%) and moistening (30.08%). The time proportion of crutching in terrestrial environment was high in species with higher terrestrialization. The aspect ratio of the pectoral fin and muscle ratio was correlated with terrestrial degrees.

This study aimed to determine the phenotypic and genotypic antibiotic resistance profile of ESBL-producing E. coliisolated from ducks. A total of 50 rectal swab samples from ducks were collected at markets in Gia Lam district, Hanoi city. The isolates in this study were all resistant to streptomycin, ampicillin, tetracycline, ceftazidime and cefotaxime. Besides, they also exhibited high resistance rates to sulfamethoxazole/trimethoprim (95.65%), gentamicin (91.3%)and chloramphenicol (91.3%). The lowest resistance rate was recorded with cefoxitin (30.43%) and 100% isolates were susceptible to meropenem. Interestingly, all of these isolates were determined as multidrug resistant strains. The result of phenotypic detection of ESBL indicated that 100% (20/20) presumptive ESBL producing E. colistrains were able to produce ESBL Among them, 50% (10/20) isolates carried blaTEM gene,25% (5/20) haboured blaCTX-M-1, 10% (2/20) habour blaCTX-M-9, and 15% (3/20) carried both blaCTX-M-1 and blaTEMsimultaneously.

The current status of soil quality in Lang Sen Wetland Reserve, Tan Hung district, Long An province was carried out to provide data on soil environmental quality for conservation,base onsoil quality parameters, i.e.pHH2O, pHKCl, electrical conductivity,total acidity, organic matters,total nitrogenandtotal phosphorus at0-20 cm and 20-50cm soil layers of sub-zone 5, 6, 9, 10, 11 and 12in the 2023 dry season. The results recorded that the soil was highly acidic with pHH2O, pHKCl, total acidity 2.60-4.27, 2.60-3.63 and 2.92-19.63 meq H+/100g soil, respectively. The organic matter and total nitrogen content of the soil were quite high, however the total phosphorus content was low and these value ranged from 8.09-24.15%, 0.29-2.27%, and 0.006-0.021%, respectively. The 0-20cm soil layer had higher pH, electrical conductivity, organic matter, total nitrogen, and total phosphorus than the 20-50cm soil layer in most sub-zones. Subzones 9, 10 and 5 had higher pH but lower total acid, organic matter, total nitrogen and phosphorus than the others.Changes in physical and chemical composition of soil in six sub-zones and twosoil layers wereheavily influenced by water management regime in the sub-zones.Soil quality is mostly suitable for the growth of dominant plant species in sub-zones, however drought condition at the end of the dry season in the sub-zones 6, 11 and 12; and continuous flooding in the sub-zones 9 and 10 should be taken into account.

The study aimed to point out the advantages, limitations and causes when sanctioning administrative violations in the field of agricultural land in Lang Son province and propose solutions to improve the sanctioning of administrative violations so that agricultural land can be used. in accordance with the law. In the period 2016-2022, there were 2,582 cases of agricultural land law violationswith 166.29ha sanctioned for land encroachment and appropriation; Illegally building houses or arbitrarily changing land use purposes, illegally transferring land, etc. Administrative sanctions have been directed and supervised regularly by all levels and branches. The person who is sanctioned for an administrative violation has complied with the decision to sanction an administrative violation. However, many cases have not been sanctioned promptly due to inappropriate regulations on sanctioning authority; limited level of legal knowledge of land users;human resources in some localities are lacking; cadastral records are not good. To sanction administrative violations promptly and accurately, it is necessary to perfect the authority to sanction administrative violations; strengthen propaganda and dissemination of laws; ensure sufficient human resources and facilities to serve the sanctioning of administrative violations; complete cadastral records.

The study aimed to investigate the effect of ingredients and foodadditives on the quality of soy yogurt. The quality attributes of soy yogurt with dragon fruit jam addition were determined using instrumental analysis. The sensory properties of the product were evaluated using the ranking method. The results showed that soy yogurt supplemented with 1.5% whey protein, 0.5%skimmed milk, 0.5% whipping cream, and stabilizers of 0.8% gelatin and 0.2% modified starch resulted in the soy yogurtwith protein content equivalent to animal-basedyogurt with 3.6% protein, 1.3% lipid, 12.0% carbohydrate, stable product texture,and highly acceptable sensoryquality.

In Vietnam, potato (Solanum tuberosum) is one of the winter crops with high economic efficiency. In addition to inorganic and organic fertilizers, the use of plant endophytic microorganisms with the ability to fix nitrogen, solubilize phosphate, and produce IAA has been proven to be a beneficial and sustainable approach for promoting crop growth. This study was conducted to isolate and investigate the applicability of eight endophytic bacterial isolates on in vitroSolara potato plants. The data indicated that all eight isolates wereable to synthesize IAA. In addition, three isolates (Iso-5, Iso-19, and Iso-21) were able to fix nitrogen. Moreover, six isolates (Iso-2, Iso-5, Iso-6, Iso-20, Iso-21, and Iso-22) were able to solubilize phosphate. Three isolates, including Iso-2, Iso-12 and Iso-22 had the ability to stimulate the growth of tissue-cultured Solara potato plants by improving plant height, root length, fresh weight, and dry weight. In conclusion, three isolates (Iso-2, Iso-12, and Iso-22) are potential bacterial isolates could be usedin in vivotesting on the growth and development of potatoes.

Cellulase was applied to improve the extraction efficiency from medicinal mushroom extracts of Ganoderma lucidumand Trametes versicolor. In addition, the study proposed the process of producing beverages from those medicinal mushrooms and chrysanthemum (Chrysanthemum indicum)flowers. The findings show that, for extracting from Yunzhi’s extract, using 3% cellulasefor 15 minutes attemperature of 70C gained the highest extraction efficiency. Meanwhile, the extraction efficiency from Lingzhi’s extract was highest with 4% cellulasein 25 minutes attemperature of 70C. Mushroom beverage with a mixture of 25% Lingzhi, 50% Yunzhi, 20% Chrysanthemum flowers, and 5% sweet grass (Stevia rebaudiana) had the highest sensory evaluation according to the TCVN3215-79. The processed product meets quality standards on food hygiene and safety according to QCVN 8-2/2011-BYT for permissible limits of heavy metals and Decision 46/2007/QD-BYT for biological and chemical contamination in food.

In recent years,some equipment of physics experiments have been damaged or reducedmeasurement accuracy because they were used for too long. Therefore, these experiments need to be improved by connecting them to computers to increase visualization and increase measurement accuracy. Research methodsisusing DataStudio software combined with the Science Workshop interface and sensors to connect experiments to computers. DataStudio is a data collection, display, and analysis program provided by PASCO Scientific. Based on this improved solution, the research groupreceivedthe followingresults:replacedthe old measurement method, introducednew experiments and and using software to process data.The main goal is to create highly accurate experiments to help learnersprocess data better and improve their skills in using modern laboratory equipment.From these innonvations, lecturers and students have more excitement and creativity during the conduct of experiments

Sustainable rice production (SRP) is one of the solutions to help increase the value of rice, while contributing to reducing greenhouse gas emissions to achieve the government's Net zero goal. Implementing and scaling-out SRP meeting standards are a challenge for the rice industry and localities. This study aimed to assess the current situation,barriers and influencing factors to propose solutions for developing the SRP in the Mekong Delta. The study surveyed 318 farming households implementing the SRP standard in 3 provinces An Giang, Dong Thap and Can Tho in 2022. Besides descriptive statistics, the study used binary regression to determine influencing factors and level of compliance with SRP standards. The results show that about 7.2% of farming households met the SRP standard. The education level of the household head, land area size and contract production exerted a positive influence on the probability of meeting the SRP standard. Proposed solutions to increase the proportion of farming households that meet SRP standards are to improve farmer capacity, increase the proportion of young people in production, and improve straw collection and stubble treatment, local service infrastructure, and contract farming according to the rice value chain approach.

This study aimed to assess the current status and propose solutions to encourage enterprises to invest in agriculture in Thai Binh province. The study surveyed information from 90 enterprises, and consulted 20 experts who are managers and scientists on policies, solutions, difficulties and obstacles when investing in agriculture in Thai Binh province. The study used descriptive and comparative statistical methods and combined with a random effects regression model for panel data to analyze the factors affecting the investment capital of enterprises in agriculture in the province. Recommendations to increase business investment in agriculture in Thai Binh province focused on raising the awareness and political determination of all levels of government; attracting key investment and unlock new growth drivers; supporting land accumulation and concentration; developing human resources associated with enterprises employing labor; increasing mobilization of resources for investment in infrastructure.