Published: 2023-08-25

Farming status, economic and technical efficiency of agroforestry models at Nui Dai, An Giang province

Nien C. Nguyen, Thao P. Pham, Nguyen H. Pham, & Dan T. Vo
Electronic version: 25 Aug 2023 | DOI: 10.52997/jad.3.04.2023
Abstract | PDF (226.5K)

Abstract

This study was carried out from November 2021 to May 2022 with the aim to evaluate the farming status, economic and technical efficiency of agroforestry model in Nui Dai, the largest mountain in the Bay Nui region, An Giang province. Via randomly interviewing 89 farmers using a structured questionnaire form, data on the status of agroforestry production, total income, and natural conditions were collected and analyzed. The results indicated that there were 13 existing farming models, including 6 agroforestry models and 7 models that grew only crop plants or forest trees. Agroforestry models accounted for 40.94% of the total annual income of households, with profits ranging from 6.71 to 23.3 million VND/ha per year. Input factors, including cultivated area, hired labor for planting, and yearly harvesting, showed a positive correlation with the income from farming models. The average technical efficiency (TE) of the farming models was 49.46%. The factors positively affecting to TE were ethnicity, farming experience and soil types, whereas the number of household members negatively affected TE.

Morphological and biological characteristics of Galleria mellonella L. (Lepidoptera: Pyralidae) reared on different artificial diets

Hoang K. Le, & Dong T. H. Tran
Electronic version: 25 Aug 2023 | DOI: 10.52997/jad.1.04.2023
Abstract | PDF (913.8K)

Abstract

The greater wax moth (Galleria mellonella L.) is a common insect used as alternative host for mass rearing and research of natural enemies. Finding appropriate artificial diets can aid in increasing the efficiency of mass rearing. The study evaluated three different artificial diets by determining some biological and morphological characteristics of greater wax moths in laboratory of Plant Protection Department, Agronomy Faculty, Nong Lam University, Ho Chi Minh City, Vietnam. The experimental results showed that the artificial diet CT2 was the most effective one of the three treatments. Its larval stage was shortest, with an average of 27.6 ± 4.2 days. The greater wax moth larvae reared on CT2 grew fast and had large size. Over a period of 20 - 30 days of age, the length and width of greater wax moth larvae ranged from 11.9 ± 5.2 to 16.3 ± 6.2 mm and 2.7 ± 1.4 to 3.9 ± 1.8 mm, respectively. The female greater wax moths laid 819.0 ± 175.5 to 1,008.1 ± 354.6 eggs on average. When greater wax moths were reared on three different artificial diets, there was no difference in fecundity. 

Selection of Arabidopsis transformants containing AtZAT12

Cham T. T. Le, & Ngoc T. Pham
Electronic version: 25 Aug 2023 | DOI: 10.52997/jad.4.04.2023
Abstract | PDF (622.5K)

Abstract

This study aimed to select Arabidopsis seeds after transformation with the AtZAT12 gene via Agrobacterium tumerfaciens. ZAT12 is a transcription factor that inhibits other transcription factors FIT through the EAR motif. FIT itself is a central transcription factor that controls Fe uptake under Fe-deficient conditions. However, if Fe is absorbed excessively, it will produce reactive oxygen species that could damage cells. That is the reason why AtZAT12 transcription is elevated and FIT transcription is inhibited under Fe deficiency for 10 days. To investigate the function, the AtZAT12 gene was inserted into the pMDC107 vector for transformation into Arabidopsis. The T0 Arabidopsis seeds obtained after floral dip transformation were placed on 1% MS agar supplemented with 15 μg/mL Hygromycin B. Beforehand, the T0 seeds were sterilized and kept in the dark for stratification. Subsequently, the seed plates were subjected to a regime of 6 h of light, 48 h of dark and 24 h of light (3.25 d). The hygromycin B-resistant seedlings had long hypocotyls (~ 1.0 cm), while the non-resistant seedlings had short (~ 0.3 cm) hypocotyls. This method took only 3.25 days to identify transgenic Arabidopsis seedlings. After that, positive transgene lines were examined by PCR method for AtZAT12, and the expression of AtZAT12 was observed under microscope.

Modeling the stem taper functions for Acacia hybrid in Dong Nai province

Them V. Nguyen
Electronic version: 25 Aug 2023 | DOI: 10.52997/jad.2.04.2023
Abstract | PDF (292.1K)

Abstract

The objective of this study was to construct appropriate stem taper functions at the individual tree level of Acacia hybrid plantations. The stem taper functions were constructed from 150 sample trees at the age of 3 - 10 years in which their diameter at breast height ranged from 4 - 24 cm. The appropriate stem taper functions were constructed and tested from 2 forms of candidate functions. The form 1 was a multivariable stem taper function and form 2 was a single-variable stem taper function. The research results showed that the deviation of the multivariable outsidebark stem taper function was 19.0% and 42.2% smaller than that of the single-variable function of order 7 and order 2, respectively. Similarly, the deviation of the multivariable inside-bark stem taper function was 13.6% and 32.8% smaller than that of the single-variable stem taper function of order 7 and order 2, respectively. Accuracy of multi-order single-variable stem taper functions was improved by constructing for each diameter class. 

Investigation of pyometra in dogs in Ho Chi Minh City, Vietnam

Huong T. T. Pham, & Thuong T. Nguyen
Electronic version: 25 Aug 2023 | DOI: 10.52997/jad.6.04.2023
Abstract | PDF (221.3K)

Abstract

The objectives of this study were to evaluate the status of pyometra in dogs and effects of treatment, and to isolate bacteria from the inflammatory fluid of pyometra in dogs. The study was carried out from September 2022 to February 2023 at the Animal Health Laboratory and Treatment Division, Sub-Department of Animal Health and Husbandry of Ho Chi Minh City. Out of total 1,715 bitches, there were 81 cases of pyometra (4.43%). The results showed that dogs aged 5 - 7 years (35.80%) had the highest rate of pyometra, followed by dogs aged 2 - 4 years (20.99%), and the lowest rate with dogs < 2 years old (3.70%). Local breeds had a lower pyometra rate (19.75%) compared to foreign breeds (80.25%) (P < 0.05). Dogs kept in cages accounted for 58.02% of the pyometra rate, which was higher than the rate of free-roaming dogs at 41.98% (P < 0.05). Non-reproductive dogs had the highest rate of this disease (64.20%), followed by primiparous dogs (25.93%) and the lowest rate was recorded in dogs with parity 5 (1.23%) (P < 0.05). Common clinical symptoms included moodiness/proneness, vaginal discharge, abdominal distension/ pain to touch, excessive drinking/thirst, loss of appetite, dehydration, fever, weight loss, polyuria and vomiting, which were important for the diagnosis of pyometra. Streptococcus was a bacterial group found in uterine fluid samples of pyometra by isolation and culture method. The treatment method chosen by the owners for pyometra in dogs in Ho Chi Minh City was surgical intervention and the effect of successful treatment was very high (90.12%)

Isolation and genetic analysis of Tembusu virus in ducks

Dat M. Truong, & Hai T. Hoang
Electronic version: 25 Aug 2023 | DOI: 10.52997/jad.5.04.2023
Abstract | PDF (197.5K)

Abstract

The experiment was conducted from August 2020 to March 2022 at the Veterinary Hospital of Nong Lam University, Ho Chi Minh City. The aim of this study was to isolate and analyze Tembusu virus gene (flavivirus) using 9 to 11 day-old embryonic duck eggs. Treated specimens were inoculated into embryonic duck eggs by allantoic route, then eggs were observed every day for 7 days. The allantoic fluids of the survival eggs were inoculated up to 3 times. Subsequently, the allantoic fluids were checked by real-time RT-PCR to detect Tembusu virus. A positive sample was then titrated, and finally a partial genome was sequenced as well as a phylogenetic tree was constructed. As a result, a strain of Tembusu virus was isolated, and genetic analysis of partial E gene showed that this virus strain was highly similar (from 96,8% to 98,15%) to others in China and Thailand.