Vol. 21 No. 2 (2023)

The objectives of this study were to identify SSRmarkers closely associated with shrunken2 (sh2)andsugary1 (su1) genesandapplication forselecting target genotypes on 30 S3 sweet corn lines. Four SSR markers closely associated with the sh2gene (umc1320, umc2276, umc1273, bnlg1257) and four SSR markers closely associated with the su1gene (umc1142, umc1031, bnlg1937, umc2061) were investigated in three check lines. The results showed that the markers umc2276 and umc1031 were suitable to identify the sh2and su1genes, respectively. Using these markers for screeningon 30 S3 sweet corn lines identified 7 lines homozygous for recessive gene sh2sh2(D04, D09, D13, D21, D22, D24, D25), 2 lines homozygous for recessive gene su1su1(D19, D30) and 2 lines double homozygous recessive for sh2sh2su1su1(D11, D14). Phenotypic evaluation confirmed the similarity to genotypes and proved high accuracy of the selected molecular markers. Total soluble solids of the sh2sh2su1su1lines were higher than sh2sh2lines and superior to that of the su1su1lines. These SSR markers and 11 selected genotypes played a vital role for the rapid development of high-quality inbred lines for specialty corn hybrid breeding in Vietnam.

This study was conducted to evaluate the semen quality of Hac Phong chickens raised at the Faculty of Animal Science, Vietnam National University of Agriculture. In the first experiment, a total of 30 semen samples from 6 Hac Phong roosters were collected in two frequencies, i.e., every day and every three days. Semen characteristics included semen volume, sperm concentration, motility, and abnormal sperm percentage. In the second experiment, rooster semen wasstored in two different media A and B at 5C. Studied parameters were tested after 8 and 24 hours of storage. The results showed that semen volume, sperm concentration, and sperm motility were higher if semen was collected every three days (P <0.05). The percentage of morphologically abnormal spermatozoa was higher if semen was collected every day (P <0.05), however, other criteria did not differ (P >0.05). When rooster semen waspreserved at 5C, the motility rate decreased from 65.38%at 8 hours to 49.84% after 24 hours of storage in medium A and from66.64%at 8 hours to 52.02% after 24 hours of storage in medium B. There was no difference in semen quality between the two media A and B (P >0.05). In both extenders, when the duration of storage was extended from 8 to 24 hours, the sperm motility decreased (P <0.05).

This study aimedto assess the current situation and propose some solutions to improve the efficiency of the implementation of the rights of land users in Ninh Binh city, Ninh Binh Province. Random sampling method was employed to select 160 land users and 30 officials for the survey and using Likert's 5-level scale for evaluation. During2017-2021periodthere were 60,361 dossiers of land use right. According to land users, 2/7 indicators were assessed atvery good level; 4/7 indicators assessed atgood level and 1 indicator atmedium level. According to the assessment of civil servants, thereweare 4/7 indicators atvery good level; 2/7 indicators are at good level and 1 indicatorataverage level. To improve the efficiency of the implementation of rights of land users, it is necessary to synchronously implement the following solutions: completingthe system of cadastral records and technical equipment; improvingthe quality of human resources.

Field surveys, in-depth interviews, SWOT analysis, and secondary data analysis were conducted to assess the status of the forest resources and the biodiversity, and the management status and challenges in biodiversity conservation of Ba Be National Park. Special-use forests in the Ba Be National Park are mainly evergreen or semi-deciduous broadleaf forests on rocky mountains with rich flora and fauna. Of the 978 species of vascular plants recorded, 34 are listed in the Vietnam Red Data Book, and 20 are listed in the IUCN Red List. Among 389 animal species listed in Ba Be National Park, there are 3 bird species, 16 mammal species, and 6 reptile species are listed in the Vietnam Red Data Book; 3 bird species, 19 mammal species, and 9 reptile species are listed in the IUCN Red List. However, forest law violations in the Ba Be National Park still take place. On the other hand, forest management and biodiversity conservation in the Ba Be National Park face many difficulties and challenges. Residents' livelihoods in the National Park's core and buffer zones highly rely on biodiversity resources and forest land.

This research was conducted to isolate, screen and identifyyeast strain capable ofproducing high quality fermented watermelon juice. The strain Saccharomyces cerevisiae M11 was selected basedon the content of alcohol, aldehyde, phenolic total, anthocynine, and antioxidant capacity in fermented watermelon juice and identified by sequencing region of ITS (Internal Transcribed Spacer Regions). The results showed that the strain M11produced highest content of alcohol (11.6 ± 0.1), phenolic total (0.06mg GAE/ml), anthocynine (0.589 ± 0.012 mg/l), and antioxidant capacity (0.589 ± 0.012 mg/l) while theanother strains (M2, M7 and M14)producedlowest content of aldehyde (57.7 ± 2.68 mg/lethanol 100)in fermented product.

Ngày nay, máy gieo hạt kiểu khí động thường sử dụng bộ phận nhận hạt kiểu đĩa thẳng đứng. Hạn chế của bộ phận gieo hạt này là hiệu suất nhận và giữ hạt thấp. Để nâng cao khả năng hút và giữ hạt trong quá trình gieo, đĩa nhận hạt trong bộ phận gieo được đặt nghiêng so với phương thẳng đứng (bộ phận gieo kiểu khí động kết hợp đĩa nghiêng). Nghiên cứu đã được thực hiện theo phương pháp nghiên cứu thực nghiệm đơn yếu tố nhằmxác định các thông số làm việc chính của bộ phận gieo kiểu kiểu khí động kết hợp với đĩa nghiêng. Kết quả cho thấy trong quá trình gieo đĩa nghiêng làm việc hiệu quả hơn đĩa đặt thẳng đứng trong việc nhận và giữ hạt. Cụ thể, các nghiên cứu tập trung xác định ảnh hưởng của các thông số chính như: áp suất hút, đường kính lỗ chứa hạt, vận tốc của lỗ chứa hạt, góc quay của đĩa gieo đến khả năng nhận và giữ hạt.Kết quả thực nghiệm cho thấy bộ phận gieo ngô kiểu khí động kết hợp với đĩa nghiêng làm việc hiệu quả với các thông số làm việc chính như sau: Áp suất chân không 50 mmHg-100 mmHg; đường kính lỗ hạt 4-5,5mm; vận tốc lỗ đĩa gieo hạt nhỏ hơn 0,68 m/s và đĩa gieo tạo với phương thẳng đứng một góc 20-35 độ.

Oil contaminants create remarkably environmental pollution problems because they have high toxicity and are recalcitrant to the environment.Bioremediation is an attractive alternative of utilizing bacteria to remove oil contaminants. In the present study, bacterial strains producing biofilm capable of degrading oil contaminants/ components were screened and some fermentation conditions with rice husk biochar as carrierto produce biodegradation product to remove oil contaminants were tested. Several microbial traditional methods such as screening, biofilm formation, fermentation, microbe denstity and total oil removal by TCVN 4582-88 were conducted. As the results, four biofilm forming bacterial strains highly capable of degrading and metabolizing hydrocarbon compounds were selected, i.e. Acinetobacter baumanniiQN01, Rhizobium sp. DG2, Rhodococcussp. BN5 and Stenotophomonas maltophilia QNG02. Fermentation on husk biochar to produce oil degrader product showed that suitable fermentation temperature was 40C and the product moisture was 40%. The product exhibited high removal efficiency (99%) for diesel oil contaminants after 7 day-incubation at the initial concentration of 10g/kg oil polluted soil.

Dragon tree (Paulownia fortunei)introduced from Canada is a woodenplantwith high economic value due to its outstanding growth rate, hightimberquality, and tolerance to insect pests and diseases. Because of exoctic origin, rapidpropagation by tissue culture to produce large quantity of planting materials isnecessary and suitable for the development of this species in Vietnam. Explants were collected from three-month-old plants. Theywere treated with 0.1% KMnO4for 30 minutes, then sterilized in 0.5% troclosenesodiumsolution for 20 minutes, followed by0.2% HgCl2for 10 minutes. Finally,the explants were soaked in 100mg/lcefotaxim solution in 10 minutes for innitialculture with survivalrate of 35.7%. The best medium for in vitroshootregenerationwas MS medium supplemented with 0.5 mg/lBAPwith the shoot multiplication rateof 5.43 shoots/explantand averageshoot height of 4.32cm. The best medium for in vitrorooting was ½ MS medium for 3weeks. Growthsubstratefor high survival rate was peatmoss (97.2%)after 3 weeksof acclimatization.

Gardenia (Gardenia jasminoidesEllis) is not only valuable as a food but also a medicinal plant used in the treatment of illnesses including jaundice, headaches, fever, inflammation, hepatic disorders, and hypertension.The current study aimed to establish an efficient protocol for in vitropropagationof Gardenia jasminoidesEllis with high multiplication rate and healthy plants. The pre-mature Gardenia fruits were the most suitable plant parts for initiation of in vitroculture. Seeds sterilized using 0.5% Presept solution for 10 minutes gave the highest sterilization (94.67%) and germination rate (90.59%). MS medium supplemented with 1.5 mg/lbenzyladenine gave multiplication rate of 7.29 shoots/explant. MS medium supplemented with 30-40 g/l sucrose and 150ml of coconut water/l gave vigorous growth of microshoots and good shoot quality. MS medium supplemented with 0.5 mg/l IBA or half-strength of MS medium recorded100% rooting rate, normal root morphology, and well growing plants.

This research aimed to understand the current situation of high -tech cantaloupe cultivation in recent years, find out existing problems so as to provide solutions which develop high -tech cantaloupe cultivation in Tay Ninh province in the future. Secondary data were collected from documents of local reports and relevant previous researches. Primary data were gathered through survey of 20 households practicing high tech cantaloupe cultivation in Tay Ninh province. Results of the research show that areas for growing cantaloupe were concentrated in urban areas where cultivated land was limited and the growers were not aware of high-tech cultivation. The packaging and preservation were not done promptly at harvest which may affect quality of product. The households did not actively access to stable consumption channel. Some solutions to develop high-tech cantaloupe cultivation in Tay Ninh province -a strong agricultural province - were recommended.

The purpose of this study was to identify the determinants of the product classificationof OCOP program in An Giang province. There are 74 OCOP products in three industries of food, beverage, and handicrafts and decoration. Standardized index method and regression analysis were used to assess the determinants of OCOP product classificaion. The results show that the factors of marketing, production organization, product story design, and product development positively affectedthe OCOP product classificaion in An Giang province.

The study wasconducted toevaluate the current situation in career orientation for students in the Faculty of Agronomy, Vietnam National University of Agriculture. A total of 310 students, 47 lecturers/supported staff, and 15 recruitment agenciesparticipated in the surveys. The results show that students were aware of their own roles and responsibilities in actively looking for future jobs withmost of the students choosingto participate in job fairs, and searching for information on the internet, newspapers, and radioto look for jobs. Career-oriented counseling for students was highly appreciated, however, several contents and operation methods are still simple and not really effective. It is necessary to organize the specialized consultants, ensuring both quantity and quality to organize career information activities well, and promote regular, continuous; and multi-disciplinary consulting activities in both content and operation.

In recent years, there have been growing interests from international researchers to study about the topic of reverse logistics, however in Vietnam, there were just few researches related to this issue. Therefore, this study aimedtoreview thefactors affecting reverse logistics implementation of businesses. Those factors are categorized into fourgroups: government -related factors, customers -related factors, social -environmental related factors and firms -related factors. This research helps practitioners working on reverse logistics to find managerial guidelines in making specific decisions.