Bangladesh Agricultural University
  • Mymensingh, Mymensingh, Bangladesh
Recent publications
Potato is one of the main food crops in Bangladesh after rice and wheat. The country is producing on average 10 million MT potatoes over the last few years. Within Asia, Bangladesh is the fourth largest potato-producing country while ranked top 15 among all over the world. All agro-ecological regions of Bangladesh are favorable for potato cultivation. It ranks second in terms of production after rice, at the same time holds the third position considering cultivated land areas after both rice and wheat. Therefore potato has a great potential to improve the socioeconomic situation of Bangladesh with minimum effort and least financial investment. For example, in recent years, it provides food security for marginal population especially during extreme monsoon and flooding. Due to its demand all over the world with the emergence of processed potato market and other diversified use, potentiality to convert this important food crops into cash crop is high for Bangladesh. Nevertheless, the country is still facing some major problems improving potato production mostly because of the lack of high yielding improved varieties while low yielding traditional potato varieties pacify around 20% potato-producing areas.
The present study aimed to determine the effects of dietary energy levels on follicular development and in vitro maturation of oocytes in pre-pubertal goats. Thirty-six female six-month-old stall-fed Black Bengal goats were divided into three equal groups that were randomly assigned to receive three iso-nitrogenous diets containing different levels of metabolizable energy (8.67, 10.20, and 11.73 MJ/kg DM). After 150 days of rearing, the weight, length and width of the ovaries increased significantly in medium and high levels of dietary energy groups than in the low-energy group. Medium and high-energy levels in the diet significantly increased the number of visible antral follicles and large antral follicles than the low level of dietary energy. The number of antral follicles per ovary was higher in high-energy fed goats than medium-and low-energy groups. The low-energy group showed more non-growing primordial follicles and degenerated follicles than the other groups. The medium-and high-dietary energy levels significantly increased the maturation rate of oocytes to metaphase II than the low-energy group. These results reveal that the level of dietary energy positively influences follicular development and meiotic competence of goat oocytes. ARTICLE HISTORY
Water stress has a significant impact on tree growth. However, the effects of watering on cambial activity and its influence on tree growth in subtropical climates is poorly understood. The present study analyzed the cambial activity on the stem of evergreen hardwood Samanea saman in response to either high frequency or low frequency watering during the pre-monsoon season in subtropical Bangladesh. We used two groups of seedlings: one group of seedlings was watered daily (high frequency watering), while the second group of seedlings was watered at 4–5-day intervals (low frequency watering). Samples for sequential observations of cambial activity by microscopy were collected from the main stems of seedlings of both groups. At the start of the experiment on March 25, 2015, during the pre-monsoon season, the cambium was inactive with no evidence of cell division. After 10 days of high frequency watering, cambial cell division and xylem differentiation were initiated. New cell plates were formed in the phloem side of the cambium. However, the cambium was inactive when low frequency watering was supplied. Supplying water in high frequency reactivated the cambium with forming small to large vessels. In contrast, the cambium remained inactive when low frequency watering was supplied throughout the experiment. These results suggest that continuous supply of water to the soil is one of the most important factors for cambial reactivation during pre-monsoon season in subtropical trees. Furthermore, our findings of artificial watering treatments might help to better understand the response of cambium to changes in precipitation patterns under natural conditions, allowing us to learn more about how cambium of subtropical trees responds to climate change.
Magnaporthe oryzae is one of the most notorious fungal pathogens that causes blast disease in cereals, and results in enormous loss of grain production. Many chemical fungicides are being used to control the pathogen but none of them are fully effective in controlling blast disease. Therefore, there is a demand for the discovery of a new natural biofungicide to manage the blast disease efficiently. A large number of new natural products showed inhibitory activities against M. oryzae in vitro. To find out effective biofungicides, we performed in silico molecular docking analysis of some of the potent natural compounds targeting four enzymes namely, scytalone dehydratase, SDH1 (PDB ID:1STD), trihydroxynaphthalene reductase, 3HNR (PDB ID:1YBV), trehalose-6-phosphate synthase, Tps1 (PDB ID:6JBI) and isocitrate lyase, ICL1 (PDB ID:5E9G) of M. oryzae fungus that regulate melanin biosynthesis and/or appresorium formation. Thirty-nine natural compounds that were previously reported to inhibit the growth of M. oryzae were subjected to rigid and flexible molecular docking against aforementioned enzymes followed by molecular dynamic simulation. The results of virtual screening showed that out of 39, eight compounds showed good binding energy with any one of the target enzymes as compared to reference commercial fungicides, azoxystrobin and strobilurin. Among the compounds, camptothecin, GKK1032A2 and chaetoviridin-A bind with more than one target enzymes of M. oryzae. All of the compounds except tricyclazole showed good bioactivity score. Taken together, our results suggest that all of the eight compounds have the potential to develop new fungicides, and remarkably, camptothecin, GKK1032A2 and chaetoviridin-A could act as multi-site mode of action fungicides against the blast fungus M. oryzae.
The southwestern coastal part of Bangladesh is highly vulnerable to different kinds of disasters due to the changing climatic conditions. With the lenses of rural communities here an approach to examine how were the different disasters experiences, what lesson they learnt and what are their present disaster associated problems and stakeholder’s networks they rely on to enhance their resilience. Qualitative data were collected through participatory rapid rural appraisal (100–150 persons), field observation, 12 focus group discussions (25–40 people/FGD), and key informant interviews (25 people) in four southwestern coastal districts and nine coastal villages of Bangladesh. Results showed that since long back to date drinking water crisis, poor roads, poverty, poor sanitation, and health problems are the main identified disaster-associated problems. After learning lessons from previous disaster experiences, the community people have improved and changed their practices mainly by storing emergency foods, house construction, and increasing disaster awareness. However, the coastal communities are combating with the problems that have both direct and indirect association with poor infrastructures. Therefore, the coastal communities urge and sketched for a better stakeholders’ supports and networks to minimize their problems and thus to enhance communities’ disaster resilience.
The eradication of staphylococcal infections has become more difficult due to the development of antibiotic resistance and virulence in biofilm-forming Staphylococcus aureus. The presence of the life-threatening zoonotic pathogen, methicillin-resistant S. aureus (MRSA), in foods indicates a public health issue. This study, therefore, aimed to determine virulence factors and methicillin resistance in biofilm-forming S. aureus isolates from different foods and food handlers. A total of 100 PCR-positive S. aureus isolates (97 biofilm formers and three non-biofilm formers) were screened using the disk diffusion method and PCR assay. By PCR, genes encoding virulence factors, e.g., enterotoxin (sea, 30%, 95% CI: 21.90–39.59%), toxic shock syndrome toxin (tst, 20%, 95% CI: 13.34–28.88%), and Panton–Valentine leukocidin toxin (PVL, 15%, 95% CI: 9.31–23.28%), were detected in the S. aureus isolates. By the disk diffusion method, 100% (95% CI: 96.30–100.00%) of S. aureus isolates were phenotypically MRSA in nature, showing 100% resistance to oxacillin and cefoxitin. Moreover, the methicillin-resistant gene mecA was found in 61 (61%, 95% CI: 51.20–69.98%) MRSA isolates. Furthermore, all the S. aureus isolates were phenotypically resistant to ampicillin and penicillin, 30% to erythromycin, and 11% to gentamycin. Among them, 51% (95% CI: 41.35–60.58%) of S. aureus isolates were phenotypically multidrug-resistant in nature, and the multiple antibiotic resistance index varied from 0.33 to 0.55. Genes encoding resistance to beta-lactams (blaZ, 100%, 95% CI: 96.30–100.00%) and tetracyclines (tetA and tetC, 3%, 95% CI: 0.82–8.45%) were found positive in the S. aureus isolates. Genes encoding virulence determinants and MRSA were significantly (p < 0.05) higher in strong biofilm-forming S. aureus than in moderate and non-biofilm-forming isolates. To our knowledge, this is the first study in Bangladesh to incorporate preliminary data on the occurrence of virulence determinants and methicillin resistance, including resistance to clinically important antibiotics, in biofilm-forming S. aureus isolates from different foods and food handlers in Bangladesh, emphasizing a potential threat to human health.
The clinical presentation of COVID-19 and the specific antibody responses associated with SARS-CoV-2 variants have not been investigated during the emergence of Omicron variants in Bangladesh. The Delta and Omicron variants were identified by post-PCR melting curve analysis of the spike (S) protein receptor binding domain amplicons. Anti-S-protein immunoglobulin-G anti-nucleocapsid (N)-protein immunoglobulin-G and immunoglobulin-A levels were measured by ELISA. The Delta variant was found in 40 out of 40 (100%) SARS-CoV-2 RT-PCR positive COVID-19 patients between 13 September and 23 October 2021 and Omicron variants in 90 out of 90 (100%) RT-PCR positive COVID-19 patients between 9 January and 10 February 2022. The Delta variant associated with hospitalization (74%, 80%, and 40%) and oxygen support (60%, 57%, and 40%) in the no vaccine, dose-1, and dose-2 vaccinated cases, respectively, whereas the Omicron COVID-19 required neither hospitalization nor oxygen support (0%, p < 0.0001). Fever, cough, and breathlessness were found at a significantly higher frequency among the Delta than Omicron variants (p < 0.001). The viral RNA levels of the Delta variant were higher than that of the Omicron variants (Ct median 19.9 versus 23.85; p < 0.02). Anti-spike protein immunoglobulin-G and anti-N-protein immunoglobulin-G within 1 week post onset of Delta variant COVID-19 symptoms indicate prior SARS-CoV-2 infection. The Delta variant and Omicron BA.1 and BA.2 breakthrough infections in the Dhaka region, at 240 days post onset of COVID-19 symptoms, negatively correlated with the time interval between the second vaccine dose and serum sampling. The findings of lower anti-spike protein immunoglobulin-G reactivity after booster vaccination than after the second vaccine dose suggest that the booster vaccine is not necessarily beneficial in young Bangladeshi adults having a history of repeated SARS-CoV-2 infections.
Tropical cyclones (TCs) are the most devastating weather phenomena that trigger massive loss of property and life in the coastal areas of the Bay of Bengal (BoB). Scientific understanding of TC occurrence can aid policy-makers and residents in coastal areas to take the necessary actions and do appropriate planning in advance. In this study, we aimed to examine the possible linkage of weather parameters with the deadly 22 TC events in the BoB from 1975 to 2014 using principal component analysis, K-mean clustering, and general circulation model (GCMs). Results showed that among 22 TCs, cluster 1 belongs to 12 TCs that occurred under the same atmospheric situation when the sea level pressure (SLP) was below 990 hPa, and the temperature ranged from 30 to 39 °C. A deep negative anomaly in SLP and temperature was observed up to 500 hPa levels. In contrast, a negative depression was found at 300 hPa geopotential height (GPH) over the study area. Cluster 2 consisted of 9 TCs when SLP was below 1000 hPa, and the average temperature was 33.5 °C. A strong negative anomaly was noticed at surface level up to 500 hPa GPH, but dramatically, this depression was completely absent at 300 hPa geopotential height over the BoB and entire coastal region. Cluster 3 contained only 1 TC when the atmospheric circumstances were completely diverse, and the SLP was above 1000 hPa. The results of the GCM model revealed that the SLP was lower, and the temperature was higher over BoB compared to the North Indian Ocean. We identified the larger depression of SLP and unpredictable temperature anomalies in the upper atmosphere that can trigger enormous unpredictability throughout the atmospheric level, leading to severe TCs. The outcomes of this study can improve our understanding of weather variables in the upper atmospheric column for forecasting the TC system more accurately in the future.
Lumpy skin disease (LSD) emerged in Bangladesh in mid-2019, leading to great economic losses for cattle farmers. This study describes the recent occurrence of the LSDV in Bangladesh and examines the clinical manifestation of the disease in local cattle breeds, characteristic epidemiological features, and pathological findings in affected animals. In addition, a full-genome sequencing of two local LSDV isolates was carried out. A total of 565 animals from 88 households were investigated, and 165 samples (skin lesions, saliva, nasal discharge, feces, and milk) were collected for virus detection. Pathology and immunohistochemistry were performed on nodule biopsies. Fever, nodular skin lesions, and swelling of the joints were the most common clinical manifestations. Skin lesions had a higher concentration of viral DNA compared to other sample types and were therefore selected for virus isolation and characterization. Pathology of the LSD skin nodules comprised a granulomatous reaction in the dermis and hypodermis that extended to the surrounding tissues. Development of the skin lesions started with swelling of keratinocytes with cytoplasmic vacuolation, vasculitis, panniculitis, thrombosis, and infarction. Altogether, the LSDV produced transmural, hemorrhagic, necrotizing, proliferative and ulcerative dermatitis. The LSD viral antigen was detected occasionally in the macrophages, epithelial cells, and vascular smooth muscle cells. The complete genome sequence analysis revealed that the two Bangladeshi field strains (BD-V392.1 and BD-V395.1) were distinct from the contemporary field strains and were closely related to the ancestral African Neethling strain. The findings of this study will improve the diagnosis, monitoring, and control of LSD in Bangladesh.
Most low- and middle-income countries lack the regulatory capacity to contain substandard and falsified (SF) medicines. Innovations for strengthening regulatory systems are needed to protect public health. We assessed the integrity of the antimicrobial supply chain in Bangladesh. We employed qualitative methods comprising policy content analysis, and literature and database reviews. Using a framework modified from the World Health Organization’s and the United States Pharmacopoeia’s, the Bangladesh National Drug Policy (BNDP), was evaluated for provisions on medicines quality assurance mechanisms. We used newspaper, peer-reviewed, and post-marketing surveillance reports to assess prevalence of SF antimicrobials. The BNDP contains provisions for quality assurance. Newspaper reports identified circulation of substandard antimicrobials. We identified only six peer-review studies testing antimicrobial product quality with three studies reporting out-of-specifications products. We suggest three strategies for strengthening the regulatory system: community-based surveillance, task shifting, and technology-enabled consumer participation.
Nitric oxide (NO) has received much attention since it can boost plant defense mechanisms, and plenty of studies have shown that exogenous NO improves salinity tolerance in plants. However, because of the wide range of experimental settings, it is difficult to assess the administration of optimal dosages, frequency, timing, and method of application and the overall favorable effects of NO on growth and yield improvements. Therefore, we conducted a meta-analysis to reveal the exact physiological and biochemical mechanisms and to understand the influence of plant-related or method-related factors on NO-mediated salt tolerance. Exogenous application of NO significantly influenced biomass accumulation, growth, and yield irrespective of salinity stress. According to this analysis, seed priming and foliar pre-treatment were the most effective methods of NO application to plants. Moreover, one-time and regular intervals of NO treatment were more beneficial for plant growth. The optimum concentration of NO ranges from 0.1 to 0.2 mM, and it alleviates salinity stress up to 150 mM NaCl. Furthermore, the beneficial effect of NO treatment was more pronounced as salinity stress was prolonged (>21 days). This meta-analysis showed that NO supplementation was significantly applicable at germination and seedling stages. Interestingly, exogenous NO treatment boosted plant growth most efficiently in dicots. This meta-analysis showed that exogenous NO alleviates salt-induced oxidative damage and improves plant growth and yield potential by regulating osmotic balance, mineral homeostasis, photosynthetic machinery, the metabolism of reactive oxygen species, and the antioxidant defense mechanism. Our analysis pointed out several research gaps, such as lipid metabolism regulation, reproductive stage performance, C4 plant responses, field-level yield impact, and economic profitability of farmers in response to exogenous NO, which need to be evaluated in the subsequent investigation.
Although urea placed deep reduces nitrogen (N) loss and increases rice yield, its use is not expanding due to the lack of effective application methods. A study was carried out to determine how different urea application techniques affected the yield and nitrogen use efficiency (NUE) of transplanted Aman rice (cv. BRRI dhan46). The experiment was set up in a RCBD design with seven treatments: T1 (deep placement of urea briquettes (DPUB) by hand), T2 (DPUB by battery-powered applicator), T3 (deep placement of prilled urea (PU) briquettes by BRRI applicator), T4 (DPUB by injector applicator), T5 (DPUB by push-type applicator), T6 (broadcast application of PU), T7 (zero-N), and three replications. Findings showed that the NH4+-N concentration in field water peaked on day 3 and then rapidly fell as time passed, while the NO3--N concentration in the water and soil was minimal. T1 reported the highest grain yield, total N content and uptake, whereas T7 had the lowest values. On T1, the apparent N recovery reached its highest level (73.5%). The NUE varied from 13.26% in T3 to 29.38% in T1. Based on this finding, deep placement of urea briquette by hand is recommended for increasing the yield and NUE of T. Aman rice.
Multidrug-resistant (MDR) foodborne pathogens have created a great challenge to the supply and consumption of safe & healthy animal-source foods. The study was conducted to identify the common foodborne pathogens from animal-source foods & by-products with their antimicrobial drug susceptibility and resistance gene profile. The common foodborne pathogens Escherichia coli (E. coli), Salmonella, Streptococcus, Staphylococcus, and Campylobacter species were identified in livestock and poultry food products. The prevalence of foodborne pathogens was found higher in poultry food & by-product compared with livestock (p < 0.05). The antimicrobial drug susceptibility results revealed decreased susceptibility to penicillin, ampicillin, amoxicillin, levofloxacin, ciprofloxacin, tetracycline, neomycin, streptomycin, and sulfamethoxazole-trimethoprim whilst gentamicin was found comparatively more sensitive. Regardless of sources, the overall MDR pattern of E. coli, Salmonella, Staphylococcus, and Streptococcus were found to be 88.33%, 75%, 95%, and 100%, respectively. The genotypic resistance showed a prevalence of blaTEM, blaSHV, blaCMY, tetA, tetB, sul1, aadA1, aac(3)-IV, and ereA resistance genes. The phenotype and genotype resistance patterns of isolated pathogens from livestock and poultry had harmony and good concordance, and sul1 & tetA resistance genes had a higher prevalence. Good agricultural practices along with proper biosecurity may reduce the rampant use of antimicrobial drugs. In addition, proper handling, processing, storage, and transportation of foods may decline the spread of MDR foodborne pathogens in the food chain.
We conducted a study over four rice seasons to assess the effects of dairy manure application on water loss, nutrient leach-ing, and rice yield compared to chemical fertilization. Water input, soil water storage, water percolation, plant growth, and yield data were recorded under triplicate field lysimeters that received either chemical fertilizers or organic manure. The lysimeters received alternate wetting and drying irrigation (5-cm after 3 days (2018 Aman season), 6 days (2019 Boro and Aman seasons), and 9 days (2020 Boro season) of ponded water disappearance) in addition to rainfall (37.5, 33.1, 40.9, and 47.4 cm, respectively). Leachate and ponded water samples were analyzed for nitrogen (N) species (NH + 4-N and NO − 3-N) and available phosphorus (P) content. Manure application increased soil water storage by 1.2-4.4 cm/m but did not affect percolation loss (44-64% of water input) in silt loam soil. The chemical fertilization had significantly higher leaching concentrations of nutrients (NO − 3-N at 0.75-3.6 mg/L and P at 0.02-0.15 mg/L) in several leaching events in the last three seasons than the manure treatment (NO − 3-N at 0.75-3.2 mg/L and P at 0-0.21 mg/L). Overall, the manure treatment reduced the leaching load of N and available P by 13% and 23.6%, respectively. The N and P concentrations in the topsoil were higher for the manure treatment. Manure application increased rice yield by 15% and water productivity by 0.07 kg/m 3 by augmenting soil water availability during the drying cycles of alternate wetting and drying processes. In addition, recycling manure in soil significantly reduced its environmental pollution compared to other inappropriate disposal methods. However, research needs remain important to adjust manure management options.
In this study, newly isolated lactic acid bacteria (LAB) were screened for the potential bioremediation capacity against toxic lead (Pb, II) and cadmium (Cd, II) with their bioaccessibility and survivability. Five strains were selected from eighteen previously isolated probiotic LAB strains based on heavy metal-resistant potentiality through in vitro disc-diffusion assay. These five strains were evaluated in vitro to explore the Pb and Cd binding and removal efficiencies using Flame Atomic Absorption Spectrophotometry. At the same time, their bioaccessibility and survivability were assessed in a dynamic in vitro gastrointestinal digestion model. The results revealed that all the tested strains were shown to have a high magnitude of minimum inhibitory concentration values ranging from 500 to 2000 mg/L with 5 to 25 mm growth inhibition zones. The results also demonstrated a significant (P < 0.05) removal of Pb and Cd among five tested LAB strains. Lactobacillus delbrueckii subsp. bulgaricus LDMB02 showed the highest removal rates of Pb and Cd. It was also revealed that these strains significantly reduced Pb and Cd bioaccessibility from 42 to 50% and 40 to 58%, respectively. Moreover, these strains were shown to have significant survivability against Pb and Cd, ranging from 80.1 to 85.4% and 81.5 to 87.5%, respectively. This study recommends the immense potential exploit of LAB as a probiotic to protect human health from the adverse effects of Pb and Cd toxicity.
Background Climate change is expected to affect plant–soil feedbacks (PSFs, i.e., the effects of a plant on the growth of another plant or community grown in the same soil via changes in soil abiotic and biotic properties), influencing plant community dynamics and, through this, ecosystem functioning. However, our knowledge of the effects of climate changes on the magnitude and direction of PSFs remains limited, with considerable variability between studies. We quantified PSFs associated with common climate change factors, specifically drought and warming, and their corresponding ambient (control) conditions using a meta-analytical approach. We investigated whether drought and warming effects on PSFs were consistent across functional groups, life histories (annual versus perennial) and species origin (native versus non-native), planting (monoculture, mixed culture) and experimental (field, greenhouse/laboratory) conditions. Results PSFs were negative (a mechanism that encourage species co-existence) under drought and neutral under corresponding ambient conditions, whereas PSFs were negative under both ambient and elevated temperatures, with no apparent difference in effect size. The response to drought was largely driven by stronger negative PSFs in grasses, indicating that grasses are more likely to show stronger negative PSFs than other functional groups under drought. Moreover, non-native species showed negative drought-induced PSFs while native species showed neutral PSFs under drought. By contrast, we found the opposite in pattern in response to warming for native and non-native species. Perennial herbs displayed stronger drought-induced negative PSFs than annual herbs. Mixed species communities displayed more negative PSFs than monocultures, independent of climate treatment. Finally, warming and drought treatment PSF effect sizes were more negative in experiments performed in the field than under controlled conditions. Conclusions We provide evidence that drought and warming can induce context-specific shifts in PSFs, which are dependent on plant functional groups, life history traits and experimental conditions. These shifts would be expected to have implications for plant community dynamics under projected climate change scenarios.
Background Antimicrobial resistance (AMR) has become an emerging threat worldwide, and developing countries such as Bangladesh are considered to be at greater risk of disseminating the resistant bacteria between human–animal interfaces. Objectives The present study was carried out to determine the prevalence and AMR profile of Escherichia coli isolated from broiler chickens, the environment, and farmworkers. This study also aimed to identify the risk factors associated with multidrug-resistant (MDR) E. coli infection in broiler chickens. In addition, the presence of carbapenem resistance gene (NDM-1) was assessed. Methods A total of 114 E. coli isolates, recovered from 150 samples (cloacal swabs = 50, farm sewage = 50, and hand washed water of farmworkers = 50) collected from 50 broiler farms, were identified by biochemical examination and polymerase chain reaction (PCR) assay. Antimicrobial susceptibility test was performed for 10 antibiotics by disk diffusion test. Carbapenem resistance gene (NDM-1) was detected by PCR. Risk factors were identified through multivariable logistic regression. Results The highest prevalence of E. coli was recorded in broiler chickens (86%) and the lowest in farmworkers (66%). For MDR E. coli infection, ‘winter season’, ‘absence of specific shoes for staff’, and ‘use of antibiotics without veterinarian's prescription’ were the significant risk factors. High resistance of the E. coli isolates was observed against levofloxacin (81.6%), doxycycline (78.1%), cefotaxime (78.1%), and ciprofloxacin (70.2%). About 76% of the isolates demonstrated MDR. None of the isolates were positive for the NDM-1 gene. Conclusions The high level and similar pattern of antibiotic resistance in E. coli isolates from broiler chickens, farmworkers, and sewage in poultry farms indicates a good possibility of spreading the antibiotic-resistant E. coli in such settings.
Red and blue light-emitting diodes (LEDs) are widely used as light sources in plant factories. Plants grown under red and blue light only produces purplish-gray light environment where plant leaves look purplish-gray. Under that light condition, it makes difficulty to check health status of plants specially insect and disease infected leaves by human naked eye. But the leaf color turns green when inspected under full spectrum of light environment. In this regard, the use of green light to red and blue create a white light environment which is congenial for the grower. Likewise, CO2 assimilation of green light is usually lower compared to red and blue light because of its lower absorptance under low PPFD. But at higher PPFD (≥500 µmol m⁻² s⁻¹), green light shows higher CO2 assimilation rate compared to red and blue light through uniform distribution of full spectrum (red, green and blue) of light into the plant canopy and the lower leaves. In this study, optimal intensity of green light supplementation to the red and blue LEDs was evaluated for better growth, yield, and quality of lettuce. In experiment I and II, green light was added with red and blue light where total photosynthetic photon flux density (PPFD) was increased for the additional green light. In experiment III, 0, 10, 20, 30, 40, 50, 60, 70, 80 µmol m⁻² s⁻¹ green (G) light was supplemented to 235 µmol m⁻² s⁻¹ red (R) and 59 µmol m⁻² s⁻¹ blue (B) light maintaining 294 µmol m⁻² s⁻¹ total PPFD. Lettuce plants were cultivated hydroponically in three-step vertical grow beds using half-strength of Enshi nutrient solution. The temperature was maintained at 20 ± 2 °C at day and night and the day length was 16 h. In experiment I and II, the fresh mass of lettuce grown under the combination of R, B and G LEDs was found higher than those cultivated under R and B LEDs only. In experiment III, lettuce plants produced high fresh masses when 30 µmol m⁻² s⁻¹ of G light was supplemented with R and B lights maintaining the ratio 211:30:53 (R:G:B). By supplementing excessive G light (≥50 µmol m⁻² s⁻¹) with R and B lights, lettuce shoot fresh mass declined. The various combinations of irradiation of R, G and B LED did not significantly affect the contents of ascorbic acid and mineral nutrients. It is recommended to supplement 30 µmol m⁻² s⁻¹ of green light to red and blue light for a higher yield of lettuce. Therefore, the suitable LED (R:G:B) combination would be 72% of red, 10% of green and 18% of blue for lettuce cultivation following recycled hydroponics in plant factories.
Background: Babesia and Theileria are potential threats to the livestock industry, causing considerable economic losses. These tick-borne blood parasites are more prevalent in crossbred cattle than local cattle in Bangladesh. Objectives: To confirm the species of Babesia and Theileria in crossbred cattle from the northern part of Bangladesh using conventional and molecular tools. Methods: A total of 385 crossbred cattle blood samples were subjected to DNA extraction and PCR. For molecular detection, B. bigemina rhoptry-associated protein 1a, B. bovis spherical body protein-4, and Theileria spp. 18S rRNA were used as the marker genes. Results: Using PCR, only 72 (18.7%) samples were found piroplasm positive, of which 12.2% Theileria, 4.7% Babesia, and 1.8% mixed infections. Both Babesia (7.3%), Theileria (7.7%) and mixed (2.8%) infections were detected in Sirajganj, and only Theileria (20.4%) was detected in Rangpur district. By PCR and nPCR we detected B. bigemina and T. annulata in Sirajganj district, and Theileria sp. in Rangpur district. The target gene sequences of isolated pathogens confirmed B. bigemina and T. annulata, and Theileria sp from these samples. Blood smears of all samples were also examined microscopically for Babesia and/or Theileria spp. and 14.3% of samples were found positive, of which 5.9% Babesia and 8.3% Theileria. Generally, the pathogens detected in Sirajgang and Rangpur were genetically related to South Asia, particularly South East Asian isolates. Conclusions: These findings provide information for a better understanding of the epidemiology of Babesia and Theileria as well as to improve the approaches for diagnosis and control of tick-borne diseases in Bangladesh.
Country bean is a grain legume extensively farmed for its multi-purpose uses, yet the traits related to yield are mainly unexplored. A study on the diversity of qualitative and quantitative morphological characteristics concerning yield among the country bean germplasms collected from Bangladesh identified considerable variation in the studied traits across the germplasms and identified a complex correlation between the qualitative and quantitative traits. Principal Component Analysis (PCA) detected five components that contributed 66.38% qualitative traits and six components contributed 74.49% quantitative traits to total variations. Eigenvalues indicated that a majority of color-related qualitative traits included cotyledon, leaf, vein, seed, flower, and petals contributed, in contrast,a majority of the seed, leaf, flower, and inflorescence-related quantitative traits contributed to the total diversity of the Lablab germplasms. Among the quantitative traits, the highest coefficient of variation (CV%) was found in average pod weight (50.98%), followed by the total number of spikes per plant (43.82%), while seed length, pod weight, length, width, thickness, number of flower/spike, spike length, and total no of spikes/plant all had more than 20.00 percent CV, suggesting suitability to use in the breeding of high yielding genotypes. The germplasms are grouped into four and three clusters based on quantitative and qualitative traits, suggesting quantitative characters offer better clustering of genotypes. Considering the above traits, our research found that the BD-10804, BD-10807, BD-11091, BD-10808, BD-10815, and BD-11089 and cultivar Goal Goda Lablab beans germplasms produced higher pod weight with corresponding higher pod length, width, and thickness suggesting to use them as high yielding genotypes for food and fodder purposes.
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2,234 members
Sharmin Aqter Rony
  • Department of Parasitology
S. M. Lutful Kabir
  • Department of Microbiology and Hygiene
Jayonta Bhattacharjee
  • Department of Surgery and Obstetrics
KHM Nazmul Hussain Nazir
  • Department of Microbiology and Hygiene
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Mymensingh, 2202, Mymensingh, Mymensingh, Bangladesh
Head of institution
Vice Chancellor, Bangladesh Agricultural University
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www.bau.edu.bd
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