Vietnam Journal of Agricultural Sciences

A genome-wide association study (GWAS) was performed to identify potential QTLs associated with salt stress tolerance in rice. The correlation between the genotyping data set and the phenotypic expression of 213 diverse rice accessions for 11 biochemical and agronomic traits was assessed. GWAS was run using a mixed linear model and population parameters previously defined in Tassel 5.0 to predict genomic regions associated with traits for the Japonica and Indica subpopulations. GWAS resulted in the detection of numerous SNP markers scattered over the rice genome that were associated with various salt tolerance traits. A QTL region on chromosome 3 was found to contribute to the variation in salt tolerance in the Indica subpopulation and related to the two traits of sheath Ca and sheath Mg contents. Three QTL regions on chromosomes 2, 4, and 5 were found to contribute to the variation in salt tolerance in the Japonica subpopulation and related to the traits of sheath Na content, sheath Mg content, the sheath Na/K ratio, leaf Na content, and the leaf Na/K ratio.

Weed management in rice cultivation faces increasing challenges due to herbicide resistance and environmental concerns, necessitating alternative, eco-friendly strategies. Among plant-based bioherbicides, Cosmos bipinnatus has emerged as a promising candidate due to its allelopathic potential. This study evaluated the efficacy of C. bipinnatus extracts in inhibiting key weed species, namely Echinochloa zcrus-galli, Leptochloa chinensis, Fimbristylis miliacea, and weedy rice (Oryza sativa f. spontanea). Bioassays demonstrated significant inhibition of radicle and coleoptile growth in these weeds, with stronger effects at higher concentrations. At 0.48 g mL⁻¹, inhibition reached 88% for E. crus-galli coleoptiles, 93% for its radicles, and 76% for L. chinensis coleoptiles. Notably, weedy rice, a major competitor in rice fields, was effectively suppressed, suggesting the potential of C. bipinnatus for integrated weed management. However, low extract concentrations (<0.06 g mL⁻¹) induced a hormesis effect, slightly promoting growth in some weeds and rice cultivars (OM380, OM5451, and OM18). Phytochemical analysis identified high phenolic (94.48 mg GAE g-1) and flavonoid (514.61 mg QE g-1) contents, particularly in leaves (45.93 mg GAE/g phenolic, 107.13 mg QE/g flavonoid) and flowers (63.89 mg GAE/g phenolic, 127.74 mg QE/g flavonoid), indicating their role as key inhibitory agents. These findings highlight C. bipinnatus as a viable biological solution for sustainable weed control, particularly against weedy rice. Further research is needed to optimize application strategies and minimize potential crop impacts, ensuring effective field applications while reducing reliance on synthetic herbicides in rice production systems.

Sesame oil is an ideal lipid source replacing the fish oil in fish diet thanks to its fatty acid profile and sensory characteristics. This study was conducted to evaluate the impacts of dietary sesame oil supplementation on growth, feed utilization, and fillet quality of Nile tilapia in growth-out stage. The basal feed for tilapia was supplemented with sesame oil at ratios of 0, 10, 20, and 40 g kg-1 corresponding to AS0, AS10, AS20, and AS40 treatments. Fish (~80g) were fed to apparent satiation for 6 weeks. Fish were weighed periodically to monitor the growth rate. At the end of the experiment, fish were dissected to collect the fillet and measure the intestinal indicators; the number of fish and amount of consumed feed served to calculate the survival rate, feed conversion ratio, and protein efficiency rate. Fillet samples were then used to analyze the fatty acid composition, chemical composition, physicochemical indicators, and sensory characteristics. The results showed that the highest value of fish growth and feed utilization were found in AS20. The sesame oil levels did not modify the intestinal parameters but changed the hardness and lightness of fish fillet. The sensory parameters including aroma and sweetness were highest in AS20 and AS40. The significant differences were recorded in total lipid and fatty acid level in fish fillet. In conclusion, the supplementation of sesame oil at 20 g kg-1 diet brings the benefits in fish growth and fillet quality of Nile tilapia in growth-out stage from 80 to 300 g/fish.

One of the main issues in using hydrogen as an alternative fuel for gasoline engines is the need to optimize the fuel supply system and adjust the air-fuel ratio to ensure a stable and efficient combustion process. This process should ensure complete combustion and avoid backfire or explosions in hydrogen engines, while also addressing the engine's efficiency when using pure hydrogen fuel. Single-cylinder, small-capacity gasoline engines are widely used in Vietnam. Using hydrogen fuel as a substitute for gasoline in these engines is still in the research phase and has not been widely implemented. This paper introduces a test model and experimental research results on the characteristics of a Honda Wave 100cc engine, which was modified to use hydrogen fuel. At an injection pressure of 2.5 bar, the torque and power varied according to different throttle levels of 50%, 75%, and 100%. The maximum torque of the hydrogen engine reached 7.3Nm at an engine speed of 5500rpm, and the maximum power reached 4.6kW at an engine speed of 6200rpm, with a minimum specific fuel consumption of about 110 g kWh-1. The experimental results showed that the maximum power of the hydrogen engine was about 70%, and the maximum torque was about 84% of that of gasoline engines. These initial research results provide a foundation for the simple conversion of traditional vehicles in Vietnam to hydrogen fuel, without requiring significant structural changes to the engine

The YABBY transcription factor (TF) family is a group of plant-specific proteins characterized by a unique structure comprised of a C2C2 zinc finger domain and a helix-loop-helix YABBY domain. These TFs play crucial roles in regulating various aspects of plant development, such as lateral organ formation and leaf polarity, as well as mediating responses to abiotic and biotic stresses. This study investigated the potential functions and expression profiles of 13 genes encoding the YABBY TF family in cassava (Manihot esculenta) under various stress conditions. Through a comprehensive analysis of promoter regions, we identified numerous cis-regulatory elements (CREs) associated with abiotic stress responses and phytohormone regulation. Specific CREs, such as low-temperature responsive elements and MYB recognize sites, were linked to cold and drought responses, respectively, suggesting their involvement in stress adaptation. RNA-Seq analysis under drought and PEG6000 treatments revealed significant transcriptional changes, with several YABBY genes being upregulated or downregulated, indicating their roles in drought tolerance and water use efficiency. Under biotic stress conditions, specifically cassava brown strike disease inoculation, YABBY genes exhibited diverse expression patterns, with notable downregulation of certain genes, suggesting their potential regulatory roles in stress responses. Taken together, these findings highlighted the diverse and critical functions of YABBY TFs in cassava's stress resilience and developmental processes.

Petunias are ornamental plants of high economic interest. A micropropagation protocol from leaf tissues of Petunia hybrid cv. ‘Pink Diamond’ was established in this study. Murashige and Skoog (MS) medium supplemented with 1 mg L⁻¹ BA and 30 g L⁻¹ sucrose was the most suitable for callogenesis and shoot regeneration from leaf explants. “Pink Diamond” cultured on this medium showed the highest callus induction rate (94.44%), the maximum shoot regeneration percentage (83.33%), the highest multiplication rate (15.28 shoots/explant), and the best quality of shoots. For the growth of shoot tip-derived shoots, MS medium fortified with 40 g L⁻¹ sucrose and 10% coconut water was the optimal medium, achieving the highest shoot length (7.78cm) and the largest number of leaves (16.89 leaves/shoot). Meanwhile, MS medium containing 40 g L⁻¹ sucrose and 15% coconut water was optimal for the growth of node-derived shoots, resulting in the largest leaf size (1.88cm in length and 0.75 cm in width) and the highest number of leaves (10.83 leaves/shoot). MS medium supplemented with 30 g L⁻¹ sucrose and 0.1 g L⁻¹ AC was the most suitable for rooting, achieving the highest shoot length (3.22cm), the largest number of leaves (7.06 leaves/plantlet), and the highest number of roots (16 roots/plantlet). The in vitro plantlets transplanted to 100% peat moss were successfully acclimatized under poly-house conditions, with an 88.39% survival rate. These plantlets reached 8.16 cm in plant height and 15.35 leaves per plant after four weeks of being transferred.

Understanding the characteristics and awareness of respondents who participated in this study is critically important for policymakers, researchers, and traders. The study was conducted by interviewing 248 households in 89 villages throughout the Central Highlands. The results showed that males of the households played a large role in responding to outsiders (about 80.6% were male respondents). The age of most interviewees ranged from 30 to 50 years old (about 55.5%). Within the interviewed households, the ethnic group distribution was 21.4% indigenous people, 75.4% Kinh, and 3.2% other minority people. Most of the respondents were poorly educated (82.0% with a high school education or lower). The number of family members ranged from 4.0 (± 0.09) to 5.3 (± 0.29) persons per household, while the number of laborers for cultivation were from 2.25 (± 0.06) to 2.62 (± 0.26) persons per household depending on ethnic group. About 88.6% of the farmers were not aware of the changes in their local agriculture production, and 78.8% of the farmers did not respond or give any consideration to future changes. However, about 40% of the interviewed farmers wanted to change their cash crops. Therefore, understanding farmers might help to raise the urgent need to support capacity building for households with relevant policies and extension programs of the Government.

This research explored the theoretical and practical dimensions of linking research and technology transfer in Vietnam's agricultural universities. Universities play a vital role in advancing agriculture through technology development, consultancy, training, and knowledge dissemination, bridging the gap between academic research and real-world applications. Key activities include negotiation, contracting, technology transfer, knowledge dissemination, and providing support services, which collectively enhance the integration of research with technology transfer processes. These activities highlight the importance of science and technology policies and mechanisms, which significantly influence the development of a robust agricultural technology transfer market in Vietnam. However, significant limitations hinder progress. Vietnam's science and technology transfer remains underdeveloped, with many innovations failing to achieve real-world applications. Current policies are overly focused on patenting, neglecting broader commercialization and practical implementation. Additionally, the lack of diverse and effective connection channels, limited public awareness, and insufficient financial and human resources exacerbate these challenges. Agricultural universities struggle to establish strong connections and drive impactful technological advancements. The study concludes that enhancing internal university capacities, coupled with supportive policies, are essential to align academic research with agricultural needs, ultimately fostering innovation and sustainable development in Vietnam's agricultural sector.