Faculty of Agriculture

SELECTION OF HEAT TOLERANT PARENTS AND THE DEVELOPMENT OF SUPERIOR HYBRIDS IN BOTTLE GOURD [Lagenaria siceraria (Mol.) Standl.]

2026-09-29T07:45:42Z

SELECTION OF HEAT TOLERANT PARENTS AND THE DEVELOPMENT OF SUPERIOR HYBRIDS IN BOTTLE GOURD [Lagenaria siceraria (Mol.) Standl.] ISLAM, MD. SHAFIQUL Rising summer temperatures in Bangladesh severely constrain bottle gourd productivity, necessitating the identification of heat-tolerant parents and the development of superior hybrids. To address this challenge, a comprehensive research program was conducted from 2022 to 2025 at the BRAC Vegetable Research Center, Dinajpur, involving fifty-eight (58) genetically diverse bottle gourd genotypes. The study aimed to assess genetic variability and screen heat-tolerant genotypes, identify superior parents through combining ability, and develop heterotic hybrids under heat stress. Initially, the 58 genotypes were evaluated under both optimum (Rabi) and heat-stress (Kharif) environments for morphological, yield contributing, and quality traits. Wide and significant genetic variability was observed for days to first female flower appearance, node number at first female flower appearance, days to first edible fruit harvest, fruit length, fruit diameter, number of fruits per plant, fruit weight, fruit yield per plant, total soluble solids, dry matter content, and ascorbic acid content. High heritability coupled with high genetic advance for most traits indicated the predominance of additive gene action and substantial scope for genetic improvement through selection. Correlation and path analyses identified number of fruits per plant, fruit weight, and fruit diameter as primary yield determinants, with earliness contributing indirectly, establishing these traits as key selection criteria under heat stress. Heat tolerance was assessed using combined stress tolerance indices of major yield-contributing traits. Based on indices values, ranking, and cluster analysis, genotypes were classified into 21 heat-tolerant, 18 mid-tolerant, and 19 susceptible groups. From these, 20 tolerant and two mid-tolerant genotypes were selected for further evaluation through line × tester analysis under heat stress conditions. Combining ability analysis identified several parents with desirable general combining ability (GCA) effects for earliness, fruit size, yield components, and yield per plant. Based on per se performance and GCA ranking, six genotypes with BG-01, BG-16, and BG-21 as strong general combiners and BG-42, BG-55, and BG-53 as moderate but trait-specific good combiners were selected for a 6 × 6 full diallel mating design. Diallel analysis conducted during Kharif 2025 under heat stress showed highly significant GCA, SCA, and reciprocal effects for all studied traits, confirming the involvement of additive, dominance, and maternal genetic components, as well as the importance of cross direction in hybrid performance. Among the parents, BG-53 and BG-21 were identified as superior general combiners for fruit yield and major yield determinants. Heterosis analysis revealed significant positive heterosis over mid-parent, better-parent, and standard checks for yield and yield-contributing traits under heat stress. The hybrid BG-53 × BG-16 exhibited maximum heterosis for number of fruits per plant and fruit yield per plant. BG-53 × BG-01 recorded the highest heterosis for average fruit weight along with substantial yield advantage. BG-55 × BG-42 showed significant heterosis for fruit diameter along with favorable yield and quality traits. Crosses BG-01 × BG-21 and BG-21 × BG-53 combined desirable earliness with high yield heterosis, indicating strong dominance and over-dominance effects under heat-stress conditions. Genotypes BG-53 (mid-tolerant, early, and prolific) and BG-21 (tolerant, with higher fruit weight and yield) were identified as key parental lines for heat-stress breeding programs. The hybrids BG-53 × BG-16, BG-53 × BG-01, BG-01 × BG-21, BG-21 × BG-53, and BG-55 × BG-42 were selected as promising for potential commercial hybrid development under heat stress in Bangladesh. SELECTION OF HEAT TOLERANT PARENTS AND THE DEVELOPMENT OF SUPERIOR HYBRIDS IN BOTTLE GOURD [Lagenaria siceraria (Mol.) Standl.]; Dissertation submitted to the Department of Genetics and Plant Breeding Hajee Mohammad Danesh Science and Technology University, Dinajpur in partial fulfillment of the requirements for the Degree of DOCTOR OF PHILOSOPHY IN GENETICS AND PLANT BREEDING BY MD. SHAFIQUL ISLAM, Registration No: 1105072, DEPARTMENT OF GENETICS AND PLANT BREEDING, HAJEE MOHAMMAD DANESH SCIENCE AND TECHNOLOGY UNIVERSITY DINAJPUR-5200, BANGLADESH; AUGUST 2026.

AGRICULTURAL DIVERSIFICATION FOR LIVELIHOOD SECURITY OF THE FARMERS IN NORTHERN BANGLADESH

2026-09-29T07:32:31Z

AGRICULTURAL DIVERSIFICATION FOR LIVELIHOOD SECURITY OF THE FARMERS IN NORTHERN BANGLADESH RASHID, MD. MAMUNUR The purposes of the study were to determine the extent and pattern of agricultural diversification and its influencing factors, to measure the level of livelihood security among diversified farmers, to examine the association between agricultural diversification and livelihood security, and to identify the constraints faced by farmers in adopting agricultural diversification along with possible suggestions to overcome them. Data were collected from August to December 2024 using a pretested interview schedule from farmers in six villages of the Kurigram, Thakurgaon, and Dinajpur districts of Bangladesh. In addition, qualitative data were gathered through focus group discussions (FGDs) and case studies. A multistage random sampling technique was employed to select 348 farmers from a population of 2,720. Fifteen selected characteristics of the farmers were considered as independent variables, while agricultural diversification was treated as the primary dependent variable. The Simpson’s Index of Diversity reveal that the average agricultural diversification index (ADI) was 0.599, indicating a medium level of agricultural diversification in northern Bangladesh. Among the three locations, Charland farmers in Kurigram district exhibited the highest ADI (0.610), followed by Upland farmers in Thakurgaon district (0.596) and Barind Tract farmers in Dinajpur district (0.588). Out of the 15 characteristics, 11 were significantly correlated with agricultural diversification. Regression analysis showed that six variables jointly explained 50.3 percent of the variation in agricultural diversification. Market accessibility contributed the most (23.2%), followed by decision-making ability (12.1%), extension media contact (6.9%), farm size (3.7%), risk orientation (3.3%), and credit-seeking behaviour (1.2%). Path analysis indicated that market accessibility, decision-making ability, extension media contact, risk orientation, and credit-seeking behaviour had direct positive effects, while farm size had a direct negative effect on agricultural diversification. The majority of the farmers (84.77%) had average to poor levels of livelihood security. A statistically significant positive association (χ² = 24.328, p < 0.01) was observed between agricultural diversification and livelihood security. The most severe constraint faced by farmers was the higher price of inputs such as seeds, fertilizers, and pesticides (CFI = 268.97), whereas untimely availability of good-quality inputs was the least severe constraint (CFI = 177.30). Overall, highest portion (70.11%) of the respondents experienced a medium level of constraints, 19.25 percent faced low constraints, and 12.36 percent encountered high constraints in adopting agricultural diversification. To overcome these constraints, farmers suggested ten measures, among which the most frequently mentioned (85.00%) was ensuring proper market facilities at the village level. AGRICULTURAL DIVERSIFICATION FOR LIVELIHOOD SECURITY OF THE FARMERS IN NORTHERN BANGLADESH; A Dissertation Submitted in accordance with the requirements of the Hajee Mohammad Danesh Science and Technology University Dinajpur for the degree of DOCTOR OF PHILOSOPHY By MD. MAMUNUR RASHID, Student No. 01/2022, Reg. No. 1005102, Department of Agricultural Extension, Hajee Mohammad Danesh Science and Technology University, Dinajpur; December, 2025.

HUMAN DOSES OF DEHP DURING PREGNANCY INFLUENCE POST-NATAL GROWTH AND REPRODUCTION IN OFF-SPRING FEMALE MICE

2026-06-25T06:18:20Z

HUMAN DOSES OF DEHP DURING PREGNANCY INFLUENCE POST-NATAL GROWTH AND REPRODUCTION IN OFF-SPRING FEMALE MICE HASAN-UZ-ZAMAN Di (2-ethylhexyl) phthalate (DEHP) is an endocrine-disrupting chemical that interferes with reproductive function and hormone regulation. Among different exposure routes (oral ingestion, inhalation, and dermal contact), the most common routes of exposure are via oral ingestion from food packaging and the use of cosmetic products, but high levels of phthalates are also present in household dust. Thus, exposure to phthalates is ubiquitous in human populations. For the general population, it was estimated that the average total daily individual ambient exposure to DEHP ranges from 0.21 to 2.1 mg/day. Thus, the estimated range of daily human exposure to DEHP is 3–30 μg/kg/day based on urinary metabolite concentrations; however, measurements of DEHP in household dust can reach up to 700 mg/kg, potentially increasing exposure levels in certain individuals. The effect of phthalate on male reproduction is now well studied; however, the effect of phthalate on female reproduction warrants extensive investigation. Because women are exposed to phthalates at a higher level than men through their widespread use of personal care and cosmetic products, In addition, it is hypothesized that phthalate can cross the placenta and interfere with the embryo, postnatal growth and development, and the later life of offspring after parturition. In this study, the Swiss albino female mice were randomly divided into four groups namely T0 (control), T1 (2mg/kg DEHP), T2 (4mg/kg DEHP), and T3 (6 mg/kg DEHP). Mating‟s strategy was followed by two virgin females and one stud male, who were confirmed pregnant by observing a vaginal plug. DEHP was exposed from the plug confirmed to parturition. After parturition, litter size (number of pups), litter weight, weight/pups, and body weight took until sexual maturity, then evaluated the reproductive cyclicity, the hormonal profile, hematological parameters, and organ developments after sexual maturity of female mice. The result showed that from birth to weaning, offspring of the T1 group exhibited a significantly body weight gain compare to the T0 group. On the other hand, considering weaning to sexual maturity, the rate of body weight gain was higher in the T1 and T2 groups compared to the T0 group. The final body weight was higher in the T2 group compared to the offspring of the T0 group. The estrous cyclicity data revealed that the rate of estrous in the T1, T2, and T3 groups were gradually decreased compared to the T0 group, in case of proestrus T1 was increased compared to T0 group but T2, T3 group were decreased compared to T0 group. The rate of diestrus in the T1, T2 and T3 groups were increased compare to the T0 group. On the other hand the rate of metestrus in the T1 and T2 group were decreased compare to T0 group but T3 was increased compared to T0 group. In the hormonal assay, the percentage of estrogen in the T1, T2 and T3 were gradually decreased compared to T0 group and the percentages of progesterone levels in the treatment groups were decreased significantly. Hematological parameters showed that the platelets in the T1, T2, and T3 groups were significantly higher than T0 group. In the term of neutrophil percentage, the T3 group was significantly lower than the other groups, Lymphocyte percentage in the T1, T2, and T3 groups were significantly higher than the T0 group. In case of total WBC count in the T1, T2 and T3 groups were increased compared to T0 group. The hematological parameters of PCT, RDW-CV, and RDW-SD were significantly lower in the T1, T2, and T3 groups than the T0 group. The percentage of monocytes in the T1, T2 and T3 were gradually decreased compared to T0 group. In cases of organ development, lung weight in the T1 and T3 groups were significantly increased from the T0 group but the T2 group was decreased from T0 group. In the T1, T2 and T3 groups, kidney and liver weight were significantly higher than in the T0 group. Heart weight in the T2 and T3 groups were significantly higher than in the T0 group. In the same way, spleen weight is comparatively higher in the T1 and T2 groups compared to the T0 group. There were no significant changes in the thyroid, uterus, or ovaries. Visual observation of the morphological characteristics of different organs showed that slight discoloration of the liver and lung was substantially affected in T3 group compared to T0 group. HUMAN DOSES OF DEHP DURING PREGNANCY INFLUENCE POST-NATAL GROWTH AND REPRODUCTION IN OFF-SPRING FEMALE MICE; A THESIS BY HASAN-UZ-ZAMAN, Student No. 1504096, Semester: July-December, 2023, Session: 2022-2023; MASTER OF SCIENCE (M.S.) IN GENETICS AND ANIMAL BREEDING, DEPARTMENT OF GENETICS AND ANIMAL BREEDING, HAJEE MOHAMMAD DANESH SCIENCE AND TECHNOLOGY UNIVERSITY DINAJPUR-5200; DECEMBER 2023.

EFFECT OF ORGANIC AND INORGANIC FERTILIZERS ON AZOTOBACTER AND CYANOBACTERIAL POPULATION AND RICE CROP IN PIEDMONT SOIL

2026-06-22T07:18:17Z

EFFECT OF ORGANIC AND INORGANIC FERTILIZERS ON AZOTOBACTER AND CYANOBACTERIAL POPULATION AND RICE CROP IN PIEDMONT SOIL RAHMAN, MD. MANSUR A study was undertaken to evaluate the combined effects of organic and inorganic fertilizers on the indigenous Azotobacter and cyanobacterial population in soil and on the growth and yield of rice for the Boro-fallow-T. aman rice cropping pattern. The study was carried out both at the field and the laboratory of the Department of Soil Science, Hajee Mohammad Danesh Science and Technology University, Dinajpur. In the field experiment, BRRI dhan28 (boro) and Kataribhog (aman) were grown following the rice-rice cropping pattern in the two consecutive years of 2009 and 2010 in Piedmont soil (AEZ#1). The study was initiated in November 2008 and was continued up to January 2011 to complete two crop cycles with boro rice (BRRI dhan28) as the first crop and T. aman rice (Kataribhog) as the second crop in each cycle. The experiment was laid out in the randomized complete block design (RCBD) with eleven treatments having three replications. The 11 treatment combinations consisting of N, P, K, S, Zn, cowdung (CD), poultry manure (PM) and mustard oil cake (MOC) including one control treatment were as follows- T0 : Control, T1 : 100 % RFD on the soil test basis, T2 : 75% RFD+25% CD, T3 : 50% RFD+50% CD, T4 : 75% RFD+25% PM, T5 : 50% RFD+50% PM, T6 : 75% RFD+25% MOC, T7 : 50% RFD+50% MOC, T8 : 75% RFD+25 % (CD, PM, MOC), T9 : 50% RFD+50% (CD, PM, MOC) and T10 : 34% CD + 33% PM + 33% MOC. Data were recorded on yields, yield components and N, P, K and S contents and uptake by the grain and straw of rice. In the laboratory indigenous cyanobacterial and Azotobacter population in soil under study were determined before transplantation, 30 and 60 days after transplanting (DAT) and after harvest of rice crops. Soil organic matter status, total N, available P, S and exchangeable K of soil were also determined at 30 and 60 DAT and after harvest of rice crop to assess the nutrient dynamics due to impose of different treatments. The results of the present investigation indicated that integration of organic and inorganic fertilizers significantly influenced the yield and yield components of rice, indigenous cyanobacterial and Azotobacter population in soil and soil chemical properties. Results showed that the highest grain yields of boro rice of 6.09 and 5.75 and those of straw of 6.86 and 7.65 t ha-1 were recorded in treatment T8 having 75% chemical fertilizer and 25% organic manures during boro seasons of 2009 and 2010, respectively. The lowest grain yields of 3.15 and 2.82 and those of straw yields of 3.88 and 3.37t ha-1 were recorded in T1 during 2009 and 2010, respectively. The highest grain yields of T. aman rice of 5.40 and 4.90 and those of straw yields of 10.21 and 11.21t ha-1 were recorded in T8 during T. aman seasons of 2009 and 2010 respectively. The lowest grain yields of T. aman rice of 2.78 and 2.28 and those of straw yields of 4.67 and 5.67t ha-1 were found in T1 during 2009 and 2010, respectively. The yield components viz. plant height, tillers hill-1, panicle length, grains panicle-1 and 1000 grain weight were significantly affected by the treatments and the maximum values were recorded in treatment T8. The highest N, P, K and S contents and uptake by rice were recorded in treatment T8. Cyanobacterial and Azotobacter population was significantly affected by the treatments. Higher cyanobacterial population was recorded in 2010 than those were observed in 2009. On the contrary, cyanobacterial population was higher in boro season than those were recorded in T. aman season of the same year. Similar pattern of Azotobacter popular was recorded during the entire period but the population was higher in boro season than those of T. aman season. Soil organic matter and nutrient status such as total N, available P, S and exchangeable K were slightly increased due to experimentation. From the overall results, it can be concluded that integration of organic and inorganic fertilizers can save 25% chemical fertilizer without any yield decline. EFFECT OF ORGANIC AND INORGANIC FERTILIZERS ON AZOTOBACTER AND CYANOBACTERIAL POPULATION AND RICE CROP IN PIEDMONT SOIL; A DISSERTATION FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN SOIL SCIENCE BY MD. MANSUR RAHMAN, STUDENT No: 0805002, SESSION: 2008; DEPARTMENT OF SOIL SCIENCE, HAJEE MOHAMMAD DANESH SCIENCE AND TECHNOLOGY UNIVERSITY, DINAJPUR, BANGLADESH.