Jahangirnagar University Journal of Biological Sciences

Molecular characterization of endophytic fungi-Daldinia eschscholtzii from Aloe vera plants in Bangladesh

2023-03-30T06:41:55+00:00

Aloe vera (L.) Burm. f. is a plant of health, beauty and medicine that is widely used in Bangladesh with high demand. An experiment was performed to find out the association of endophytic fungus with Aloe vera leaves and to assess their growth behavior on different culture media, temperatures and pH. The endophytic fungus-Daldinia eschscholtzii (Ehrenb.) Rehm. was identified based on the morphological and molecular characterization using the ITS-rDNA sequence. Various solid culture media were used to assess the fungal growth, and temperature regimes i.e., 15℃, 20℃, 25℃, 30℃, 35℃ were investigated. The fungal endophyte showed maximum mycelial growth on Potato Sucrose Agar followed by Potato Dextrose Agar and Carrot Agar media. Optimum growth and development of the endophyte was recorded at temperature 25 to 35℃. We observed the effect of five different pH conditions, viz., 5, 6, 7, 8, 9 on the mycelial growth of the fungus. However, the fungal endophyte was very insensitive to the pH of the substrate. To the best of our knowledge, this is the first known occurrence of D. eschscholtzii as an endophyte in Aloe vera in Bangladesh.

Jahangirnagar University J. Biol. Sci. 11(1 & 2): 1-11, 2022 (June & December)

Effects of sodium chloride salinity on growth and yield of BARI Sunflower-2 (Helianthus annuus L.)

2023-03-30T06:43:11+00:00

A pot experiment was conducted to assess the effect of seven different NaCl solution treatments, namely 0, 50, 100, 150, 200, 250 and 300 mM on the growth and yield of BARI Sunflower-2 under sodium chloride stress. Growth parameters such as plant height, leaf number, leaf length, leaf width and leaf area showed a gradual decrease from50 mM to the highest treatment level. Sodium chloride stress caused a significant reduction in early stage growth parameters (15 Days after treatments (DAT), while at 45 DAT the percentages of various growth parameters compared to the control plant at the highest treatment level (300mM) except leaf area. Seed yield per plant and weight of 100 seeds were reduced, respectively by 27.69 and 28.44%at 300 mM salinity, while at moderate salinity (200 mM) seed yield per plant and weight of 100 seed were 83.28 and 84.12%, respectively, as compared to in compared to those of the control plants. The results obtained in the present study showed that the BARI Sunflower-2 cultivar is a moderately salt tolerant plant.

Jahangirnagar University J. Biol. Sci. 11(1 & 2): 13-20, 2022 (June & December)

Karyotype comparison and characterization of two cauliflower cultivars from Bangladesh

2023-03-30T06:43:14+00:00

Two cauliflower cultivars were karyotyped for correct characterization after orcein staining. Both cultivars have a simple chromocenter type of interphase nuclei and a gradient type of prophase chromosomes, indicating that they descended from a common ancestor. In addition, both strains were found to have 2n=18 chromosomes with an almost identical range of chromosome lengths. In terms of overall length, the white snow cultivar is almost 7 m shorter than the fresh market cultivar, indicating the presence of chromatin length diversification between specimens. In none of the cases was there a noticeable gradual decrease in chromosome length. The metacentric and submetacentric chromosomes were observed in both samples examined. Apart from other karyotypic features, TF, Syi and AsK % indicate the moderately symmetrical nature of the karyotype. As a result, the two cultivars of cauliflower were moderately primitive in nature. The collection of this karyotypic data will aid in the authentic characterization of the two cauliflower cultivars, which is essential information for the breeding program.

Jahangirnagar University J. Biol. Sci. 11(1 & 2): 21-30, 2022 (June & December)

Establishment of a suitable regeneration protocol for rapid propagation of Piper nigrum L. through in vitro culture

2023-03-30T06:44:23+00:00

An experiment was performed to establish a suitable regeneration protocol for the rapid propagation of Piper nigrum L. using nodal segments and leaf tissues as explants through direct and indirect organogenesis. After surface sterilization, several types of explant were inoculated onto gelled MS medium containing various concentrations and combinations of growth regulators for callus and direct shoot induction. The highest callus induction frequency was 92% and 84% in the case of leaf tissues and nodal segments, respectively, in gelled MS medium containing 2.0 mg/l 2,4-D. Multiple shoots (6.43±0.35 shoots per unit callus) were obtained when the calli from both explant types were cultured on MS medium containing 1.0 mg/l BAP. Nodal segments showed the best result (85%) in terms of direct shoot induction in MS medium supplemented with 1.5 mg/l BAP, where the highest number of shoots per explant was 5.03±0.69. The directly induced shoots were multiplied and elongated on MS medium containing 1.0 mg/l BAP and 0.5 mg/l IBA, the number and length of regenerated shoots per culture being 6.07±0.39 and 5.84±0.65 cm, respectively. The best response to root induction (86.67%) was observed when shoots were transferred to ½ strength of gelled MS medium supplemented with 1.5 mg/l IBA within 16-24 days, with 13.60±1.76 roots per shoot unit. The well-rooted shoots were successfully acclimated in a mixture of soil, sand, and compost (1:1:1) with a survival rate of 88%.

Jahangirnagar University J. Biol. Sci. 11(1 & 2): 31-40, 2022 (June & December)

A checklist of wild mushroom diversity and distribution in the Jahangirnagar University campus area, Bangladesh

2023-03-30T06:46:30+00:00

This comprehensive study focuses on a checklist survey of wild mushrooms and documents their morphological variability and diversity at Jahangirnagar University, a natural and social forest area in Bangladesh. Through field studies on the campus grounds from June to October 2021, 60 samples were collected from which 40 species were identified by morphological characters, belonging to 33 genera, 26 families, and 10 orders. Most species were identified from the order Agaricales and the highest frequency (83.33%) from the orders Polyporales and Agaricales. The highest species abundance was 83.33% for Ganoderma spp., Crepidotus applanatus and the density was 70% for Marasmiellus candidus. The dominant species were Ganoderma spp., Coprinus disseminates, Marasmius spp., Schizophyllum commune, Calvulina coralloides. The wild mushrooms were prevalent in the natural forest areas of the Jahangirnagar University campus. As far as we are aware, this report is the very first work on wild mushrooms or macro-fungi on the campus of Jahangirnagar University. This survey shows that the campus grounds are enriched with a wide variety of wild mushrooms.

Jahangirnagar University J. Biol. Sci. 11(1 & 2): 41-67, 2022 (June & December)

Antibiotic resistance pattern of Salmonella typhi in patients attending a teaching hospital in Bangladesh

2023-03-30T07:08:25+00:00

Enteric fever or typhoid is caused by the human-specific gram-negative pathogen Salmonella enterica serovar typhi (S. typhi). The incidence of typhoid fever remains high in rural areas and the emergence of multidrug resistance has exacerbated the situation. The present study examined the antimicrobial susceptibility patterns of Salmonella typhi to the antibiotics commonly used in Bangladesh. This study also examined the status of prescription antibiotic use. From July 2016 to June 2017, a total of 40 bacterial pathogens were isolated from blood samples from 100 clinically suspected patients at a teaching hospital in Savar, Dhaka. The blood samples were subjected to analysis byWidal test, microscopy, culture and susceptibility testing using conventional bacteriological methods. A total of 40% of cases had an established bacterial etiology with S. typhi. The highest antimicrobial susceptibility to S. typhi was observed for meropenem (77.5%), gentamicin and imipenem (72.5%), and cefotaxime (70%), respectively. The maximum resistance was observed in the penicillin group, such as (80%) followed by cotrimoxazole (75%). Carbapenem-type beta-lactam antibiotics (meropenem, imipenem) and third-generation cephalosporins (cefotaxime, ceftriaxone, and ceftazidime) were the most effective drugs for typhoid fever. Prescription survey results in four cities in Bangladesh showed that typhoid patients were mainly prescribed third-generation cephalosporins such as cefixime (36.73%) and ceftriaxone (18.37%). The findings are important for an adequate identification of the pathogens and their antibiotic resistance for the correct selection of antibiotics in typhoid fever. The study has implications for the development of guidelines for prescribing antibiotics for typhoid fever in Bangladesh.

Jahangirnagar University J. Biol. Sci. 11(1 & 2): 69-79, 2022 (June & December)

Integrated management of flea beetle and thrips on mungbean in coastal habitat

2023-03-30T07:09:12+00:00

An experiment was conducted to evaluate the effectiveness of five IPM packages in controlling flea beetles and thrips on mungbeans. The results showed that the lowest number of flea beetles (1.67/plot), the highest reduction in flea beetle population the over control (72.17%), the lowest leaf area damaged (3.33%) and the lowest percent reduction in damaged leaf area versus control (72.99%) was recorded from plots treated with Package 2 (Virtako 80WG @ 0.15 g/L water + white sticky trap). The lowest number of thrips populations (1.00/20flowers), the highest reduction in thrips population versus control(85.0%), the lowest number of damaged flowers (2.33/plant), and the highest reduction in infested flowers over control (79.44%)observed in plots treated with Package 1 (Bioneem plus 1% EC at the rate of 1 ml/L water + white sticky trap). There was a negative correlation between the numbers of flea beetles and thrips with total yield. A negative relationship was observed between flea beetle leaf area infestation and total yield, and between thrips flower infestation and total yield from different IPM packages. This study concluded that IPM package 2 was the most effective package for controlling flea beetles and IPM package 1 was good enough for controlling thrips in mungbeans.

Jahangirnagar University J. Biol. Sci. 11(1 & 2): 81-91, 2022 (June & December)