Department of Botany

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Cytogenetics of selected plant species affected by industrial effluents
(University of Dhaka, 2014-07-09) Nahar, Kazi Kamrun
Two plants viz. Colocasia esculenta (L.) Schott and Ipomoea aquatica Forssk. commonly growing in the industrial effluent affected areas were selected to observe the effect of industrial effluents on chromosomal and DNA level. Five different industrial areas such as (i) Powertex Fashion Ltd., Gazipur (ii) Shetu Pesticide Ltd., Savar (iii) Salma Leather Industry, Hazaribagh (iv) Monno Ceramic Industries, Nayarhat, Dhamrai and (v) Acme Laboratories Ltd., Tulivita, Dhamrai were selected for this study. A number of different experiments like physico-chemical parameters, essential elements, heavy metals, conventional and fluorescent karyomorphology and RAPD have been done for comparative study with control. The amount of heavy metals in soil, water and plant samples were higher in all affected areas. Dissolved Oxygen was found bellow the permissible limit in all the affected areas (lowest 0.88 mg/l in Hazaribagh) indicating high amount of organic wastes discharge from tannery. Heavy metal uptake in Colocasia esculenta is much higher than Ipomoea aquatica. The edible portion consumed more heavy metal than root. Diploid chromosome number 2n=28 was found in Colocasia esculenta collected from Gazipur garments, Savar pesticide and Hazaribagh leather area as well as control. However, 2n=38 chromosomes of the same species were observed in the sample plants collected from Monno Ceramic and Acme Laboratory area. The probable reason for increasing chromosome number was either the sample a new cytotype of the species or some irregularities occurred during cell division. On the other hand, 2n = 30 chromosomes were observed in all plant samples of Ipomoea aquatica including control. In case of both the species, the nature of staining of interphase nuclei and prophase chromosomes of the sample plants were different than those of control. The fluorescent karyotypes of both the species showed significant differences among the samples and with control as well. Fluorescent banding (CMA and DAPI) revealed the probable occurrence of deletion and tandem duplication. The different plant samples of both the species had characteristics RAPD fingerprinting. Lacking of some DNA fragments in some sample plants (which presents in the control plants) may correlate to the deletion of chromosomal parts. Similarly some new fragments in the sample plants (which not found in the control) may corresponds with the tandem duplication of the chromosomal part. Therefore, the substances present in the industrial effluents affected on the chromosome and DNA level of Colocasia esculenta and Ipomoea aquatica.
Characterization of some cotton germplasms through molecular cytogenetics
(University of Dhaka, 2015-01-20) Sultana, Syeda Sharmeen
Eleven germplasms of Gossypium hirsutum L. (cotton) released by Bangladesh Cotton Development Board viz. CB-1 (Cotton Board-1), CB-2, CB-3, CB-4, CB-5, CB-6, CB-7, CB-8, CB-9, CB-10 and CB-11 were investigated cytogenetically and at the molecular level using RAPD- and SSR- markers for authentic characterization. The 11 cotton germplasms represented a broad spectrum of variation for several phenotypic and agronomic traits. These germplasms were found to possess a prominant nucleolus in the interphase nuclei and prophase chromosomes after orcein staining. The interphase nuclei and prophase chromosomes of these germplasms showed different types of orcein-staining pattern. Although the germplasms were found to possess 2n = 52 chromosomes, differed in respect of other karyotypic features such as total length of 2n chromosome complements, number of satellites, range of relative length, centromeric index etc. The centromeric formula of 46m + 6sm were found in CB-1 and CB-4 while it was 48m + 4sm in CB-8 and CB-10. The rest germplasms have 52 metacentric chromosomes. A wide range of CMA-positive bands (5-20) was found in the metaphase chromosomes of 11 germplasms. Different number of satellites such as 4 (CB-1), 6 (CB-2), 6 (CB-3), 2 (CB-4), 3 (CB-6), 2 (CB-7), 6 (CB-8) and 6 (CB-10) were found after CMA-staining. Entirely DAPI-fluoresced chromosomes were frequent in these germplasms. The number, location and distributions of GC- and AT-rich repeats are specific for each germplasm. Fluorescent banding revealed the occurrence of genomic alteration within these germplasms. DNA from the 11 cotton germplasms was studied with 10 oligonucleotide primers and 5 microsatellite primer pairs for RAPD and SSR assay, respectively. The ten RAPD primers generated 335 distinct bands with 100% polymorphisms indicated highly diversed nature. In addition to polymorphism, 29 unique RAPD sequences were identified in 11 cotton germplasms. The five SSR primer pairs generated 69 distinct bands of which 39 were considered as polymorphic (56.52% polymorphisms). Moreover, four unique SSR sequences were identified in CB-1, CB-5 and CB-9. The combined RAPD and SSR dendrogram made CB-11 distinct from the rest and placed alone in a separate cluster that correlated with its phenotypic, agronomic and cytogenetical features. Therefore, each germplasm could be characterized authentically by cytogenetical and molecular analysis.
Physiological diversity amongst tryptophan auxotrophs in Neurospora crassa
(University of Dhaka, 2015-01-21) Beauty, Selina Parvin
Conidia of Ema of Neurospora crassa were treated with 1.168% concentration of formaldehyde (HCHO) for 10 minutes and 3% concentration of ethyl-methane sulphonate (EMS) for 12 hours and produced 4 types (albino, vigorous, fluffy and ropy) and 5 types (buff, conidial-band, albino, ropy and fluffy) of morphological mutants respectively. Mutants showed variation in their conidial germination, linear mycelial growth and weight of dry mycelia. UV irradiation of conidia of Ema at a wave length of 254 nm for 90 seconds produced 6 types (albino, buff, conidial-band, fluffy, ropy and vigorous) of morphological and 3 types (tryptophan, arginine and leucine) of biochemical mutants. Complementation test of all the seventeen tryptophan mutants were made with all the tryptophan standard markers trp-1a (10575), trp-2a (75001), trp-3a(C83), trp-4a (Y2198), and trp-5a (A420). It was found that four mutants belong to trp-1, seven mutants belong to trp-2, two mutants belong to trp-3, two mutants belong to trp-4 and two mutants belong to trp-5. On the basis of their specific growth requirements physiological diversity was detected amongst the seventeen tryptophan auxotrophs. The mutants fall into three categories namely anthranilic acid requiring (9 mutants), indole requiring (6 mutants) and tryptophan requiring (2 mutants). Inter allelic complementation studies of seventeen trp auxotrophs reveal that trp-1 auxotrophs comprises two heterocaryon groups (I and II) and two complons (A and B). trp-2 auxotrophs comprises three groups (I, II, III) and two complons (A and B). Auxotrophs of trp-3, trp-4 and trp-5 do not show any inter allelic complementation and no heterocaryon grouping amongst themselves. Linkage studies of seventeen auxotrophs with marker representatives of all the seven linkage groups reveal that trp-B13a, trp-B21a, trp-B41a and trp-B51a are linked with leu-1 of linkage group-III; trp-B8a, trp-12a, trp-B14a, trp-B22a, trp-B28a, trp-B38a and trp-B42a are linked with trp-2 of linkage group VI; trp-B17a and trp-B54a are linked with arg-2 of linkage group IV; trp-B5a and trp-B55a are linked with leu-5 of linkage group-5; trp-B11a and trp-B33a is linked with leu-3 of linkage group 1 and arg-5 of linkage group II respectively. Fine structure map of trp-1 with leu-1(33757) as a marker comprises about 10.120 centimorgan and fine structure map of trp-2 with lys-5(DS6-85) comprises 3.235 centimorgan. Cross feeding test of seventeen trp auxotrophs reveals three groups, Group-A, Group-B and Group-C. Nine anthranilic utilizing mutants belong to Group-A (B5a, B8a, B12a, B14a, B22a, B28a, B38a, B42a and B55a). Six indole utilizing mutants belong to Group-B (B11a, B13a, B17a, B41a, B51a and B54a). Two tryptophan utilizing mutants belong to Group-C (B21a and B33a). Group-A mutants grow in the filtrate of Group-B and Group-C. Group-B mutants grow poorly in the filtrate of Group-C only. Group-C mutants do not grow in the filtrate of either Group-A or Group-B mutants.
Molecular characterization of peanut (Arahcis hypogaea L.) germplasms in Bangladesh
(University of Dhaka, 2015-01-21) Habib, Md. Ahashan
Eleven varieties of peanut (Arachis hypogaea L.) were investigated cytogenetically and at the molecular level using Random Amplified Polymorphic DNA (RAPD) and Simple Sequence Repeat (SSR) primers for authentic characterization. All varieties were found to possess 2n= 40 chromosomes, except BARI Cheena Badam-7 and BARI Cheena Badam-8, where a small extra chromosome found in addition to 2n=40 chromosomes in several cells. The extra chromosome may be considered as B-chromosome and this is the first report of B-chromosome in Arachis hypogaea. One pair (XX) of small chromosomes was found in all varieties. The 11 varieties showed distinct centromeric formulae viz., i) 34m+6sm, ii) 36m+4sm, iii) 38m+2sm, iv) 32m+ 8sm and v) 40m. All varieties of peanut have distinct CMA- and DAPIbanding patterns. The number, location, intensity and percentage of GC- and AT-rich repeats were different in these varieties. Asymmetry banding pattern in homologue members indicated minute chromosomal alterations. Similar numbers of CMA and DAPI bands were observed in different stages of cell cycle revealed that the GC- and AT-rich repeats were very stable in each variety. Few chromosomes could be used as marker chromosomes of respective variety due to their unique banding pattern. Genetic diversity analysis among 11 peanut varieties was performed through polymerase chain reaction (PCR) using RAPD and SSR primers. Eight arbitrary oligonucleotide RAPD primer and four pairs of SSR primer were used for DNA fingerprinting. In case of RAPD, a total of 272 bands were produced in all the 11 peanut varieties with an average of 34 bands per primer. Based on the banding pattern 71.69% polymorphisms observed among the peanut varieties. The molecular size of the amplified DNA fragments ranged from 400 to 3000 bp. Eight unique bands were amplified from the genome of the 11 peanut varieties. 62.06% polymorphic fragments and a unique band of 50 bp were found in four SSR primer pairs. The size of the amplified bands ranged from 50 to 246 bp. The values of pair-wise genetic distances ranged from 0.1226 to 0.5500, indicating the presence of wide genetic diversity. The highest genetic distance (0.5500) was found between Dhaka-1 vs BARI Cheena Badam-8 while the lowest (0.1226) between BINA Cheena Badam-2 vs BINA Cheena Badam-3 and Tridana Badam (DM-1) vs Basanti Badam (DG-2). Dendrogram based on Nei’s (1972) genetic distance was constructed using Unweighted Pair Group Method of Arithmetic Means (UPGMA) segregating the 11 varieties of peanut into two major clusters C1 and C2. BARI Cheena Badam-7 and BARI Cheena Badam-8 were distinctly related from the rest. Therefore, each variety could be characterized by combined cytogenetical and molecular features which would be helpful for future breeding programme. en_
Molecular characterization in different cultivars of cicer arietinum L.
(University of Dhaka, 2015-01-22) Begum, Kazi Nahida
Nine cultivars of Cicer arietinum L. (chickpea) released by Bangladesh Agricultural Research Institute (BARI) viz BC1, BC-2, BC-3, BC-4, BC-5, BC-6, BC-7, BC-8 and BC-9 were investigated cytogenetically and at the molecular level using isozyme, SDS-PAGE, RAPD- and SSR-markers for authentic characterization. The nine chickpea cultivars have certain spectrum of variation for several phenotypic and agronomic traits. A prominent nucleolus was found in the interphase nuclei and prophase chromosomes after orcein staining in each cultivar. Although the nine cultivars were found to posses 2n=16 metacentric chromosomes, differed in respect of other karyotypic features such as total length of 2n chromosome complements, range of relative chromosome length and orcein staining pattern of interphase nuclei and prophase chromosomes. The number of CMA positive bands was 2 to 6 in the metaphase chromosomes of nine cultivars with percentage of GC-rich repeats ranging from 2.66 (BC-8) to 14.52 (BC-2). Each cultivar had distinct CMA- banding karyotype formula. Heteromorphicity in CMA banding revealed the occurrence of paracentric inversion in chromosome pair II of BC-2. The number of DAPI bands was ranging from 1 (BC-4) to 4 (BC-1, BC-5, BC-6, BC-7 and BC-9). DAPI bands were confined to centromeric and terminal regions of chromosomes among nine cultivars. Some DAPI bands were so unique that these chromosomes could easily be isolated from the rest and may use as marker chromosomes for the respective cultivars. Each cultivar has characteristic DAPI-banding formula. Heteromorphicity in DAPI banding pattern between homologue members indicated the occurrence of deletion. Differential staining property of satellites revealed the stain specific nature of satellited portions. The nine cultivars showed different SDS-PAGE pattern. Cultivar BC-2, BC-6, BC-8 and BC-9 could be characterized by SDS-PAGE bands on the basis of their location, size and intensity. Three isozymes system namely acid phosphatase, esterase and peroxidase were investigated of which esterase found suitable for producing distinct polymorphic band among nine cultivars. DNA from the nine chickpea cultivars was studied with 12 oligonucleotide primers and 10 microsatellite primer pairs for RAPD and SSR assay, respectively. The ten RAPD primers generated 351 distinct bands with 91.61% polymorphisms indicated highly diversed nature. In addition to polymorphism, 19 unique RAPD sequences were identified in nine chickpea cultivars. The ten SSR primer pairs generated 143 distinct bands of which 62 were considered as polymorphic (43.36% polymorphisms). Moreover, one unique SSR sequence was identified in BC-5. The combined RAPD and SSR dendrogram made BC-8 and BC-9 distinct from the rest and placed in a separate sub cluster that correlated with their phenotypic, agronomic and cytogenetical features. Therefore, each germplasm could be characterized authentically by cytogenetical and molecular analysis. This information will be helpful for characterizing each cultivar of chickpea for improved breeding program.
Comparative ecology of selected herbs and shrubs in relation to soil moisture and soil types
(University of Dhaka, 2015-03-19) Sultana, Sabiha
Eco-physiology and nature of adaptation of Cassia tora, C. occidentalis and C. sophera the pioneer of dry derelict land were investigated in relation to environmental conditions. Comparative study with these three Cassia spp. was carried out with reference to germination eco-physiology and seedling growth in relation to seed storage, salinity and pH; growth in relation to wet (W) and dry-moist (DM) conditions; sun (100% light) and shade (15% light) treatments and tissue water relation in their ecological significance. The objectives of the present investigation were to know the reasons of abundance of C. tora and low population or causes of the absence of Cassia occidentalis and Cassia sophera in the natural habitat. Seed morphology of these species showed variation in colour, size and shape and also showed similarities and dissimilarities. Freshly harvested, one week , one month and three months old seeds showed very little germination in Cassia tora ; in contrast freshly harvested seeds of Cassia occidentalis and Cassia sophera showed better germination than Cassia tora. However, the scarified seeds of Cassia occidentalis and Cassia sophera showed high percentage of germination. The effect of salinity on germination of three Cassia spp. was investigated to know their degree of tolerance at different concentrations of NaCl solution and showed a strong effect on the percentage of seed germination. Germination percentage was decreased in all the three species with the increase of the NaCl concentrations and showed lowest germination at 0.1M NaCl. Lack of germination of normal seeds of C. occidentalis and C. sophera at 0.2M and 0.5 M NaCl concentrations indicated their sensitivity to salinity. The seedling length of C. tora at 0.05M NaCl was significantly (p=0.05) decreased to 5.71cm and further increase of salinity to 0.1M, the seedling length was decreased to less than one third (2.15 cm) from that of control (6.92cm). Seeds of all the species failed to germinate at 0.5M NaCl solution. Different pH levels did not show any significant (p=0.05) difference in seedling growth except Cassia sophera which at acidic pH significantly (p=0.05) decreased seedling length and dry weight. As far as germination and early establishment are concerned it was established that low germination percentage in C. occidentalis and C. sophera, and sensitivity to salinity are the factors most likely to exclude the growth, and adaptation in the natural habitat. The three species grown in wet (W) and dry-moist (DM) conditions and at two light intensities (sun-100% light and shade 15% light) in potted soil to explain the nature of adaptation. Vegetative growth was vigorous in all water regimes in the early stages of growth of three Cassia spp. The roots of wet plants were on the top 1-2 cm of the soil surface, stunted and dark brown to black in colour. In contrast, the roots were penetrated deep into the base of the pot in DM treatment. The individual leaves of C. tora, C. occidentalis and C. sophera at different stages of development were found to be progressively larger with taller petiole (approximately 70-135 mm) as soil water was decreased i.e. in DM treatment. There was a progressive increase in leaf size, leaf area with the decrease of soil moisture in all three Cassia spp. At dry moist treatment C. tora started flowering 3 weeks earlier than wet treatment; under DM condition C. tora showed flowering 12 weeks earlier than C. occidentalis and 17 weeks earlier than C. sophera. In wet treatment there is no flower and fruit production at all in C. occidentalis and C. sophera. However, C. tora shows very poor flowers and fruit production under wet condition. Root growth was poor in wet condition. In the dry-moist treatment the largest component of the plant is leaf material in all three Cassia spp. Vegetative growth under sun (100% light) treatment was more vigorous than shade (100% light) condition. At sun (100% light) treatment C. tora showed earlier flowering than C. sophera and C. occidentalis . The relation between leaf water content and stomatal closure, the rate of transpiration and the relative turgidity under two different soil moisture (wet and dry-moist) and two light (sun and shade) treatments were investigated. The plant showed contrasting behavior with respect to transpiration rate, stomatal behavior and the development of water deficits. Highest total transpiration rate was observed in C. occidentalis followed by C. sophera and C. tora. In all the species, there was a relation between the total water and stomatal water loss. The value of RT was very similar between sun and shade conditions in Cassia spp. except C. sophera where the value of sun condition is significantly lower (p=0.05) than shade condition.
Angiospermic flora of Gazipur district, Bangladesh
(University of Dhaka, 2015-12-06) Tabassum, Rehana
1. A total of 833 taxa under 489 genera and 126 families have been recorded from the area of Gazipur district. Among the taxa recorded, the number of taxa under Magnoliopsida and Liliopsida are 605 and 228 respectively. Magnoliopsida consists of 98 families and 369 genera, while Liliopsida consists of 28 families and 120 genera. This is the outcome of 40 trips in 95 localities of the district covering forest areas, plain land, village thickets and wet lands, as well as herbarium specimens and relevant literature survey. 2. The families have been arranged according to Cronquist’s system of classification (1981). 3. Dichotomous bracketed keys to the families, genera and species have been provided. The genera and species have been arranged alphabetically under each family. 4. Original citation of each taxon with valid name and important synonyms, local name and English name (when available), brief description, chromosome number, flowering and fruiting time, ecological notes, distribution, uses and specimen examined have been provided. 5. Habitat, duration of life-span, phenology, status of occurrence, economical importance of the species and also locations are provided. Exotic taxa are specified as well. 6. Of the total number of taxa, herbs are represented by the highest number (463= 55.58%), followed by trees (174= 20.89%), shrubs (116= 13.93%), climbers (75= 9.0%), epiphytes and parasites taxa constitutes less than 1% of the total angiospermic flora. 7. The phenology of the species shows much seasonal overlapping. In the rainy season 380 species produce flowers/ fruits, in winter 367 species produce flowers/ fruits, while 86 species produce flowers/ fruits throughout the year. 8. Out of 833 angiospermic taxa recorded, 160 species (19.23%) appear to be exotic, of which 48 are trees, 30 shrubs and 82 herbs including climbers. 9. Of the recorded taxa, 766 appear to be important from ecological and/ or economic point of view. 10. In the study area the following species have been recorded only once and hence considered as rare in the area: Ecbolium ligustrinum (Vahl) Vollesen (Acanthaceae), Entada rheedii Spreng. (Mimosaceae), Hygrophila schulli (Buch.- Ham.) M. R. & S. N. Almeida (Acanthaceae), Leea alata Edge. (Leeaceae), Pterospermum semisagittatum Buch.-Ham. ex Roxb. (Sterculiaceae) and Strobilanthes scaber Nees (Acanthaceae). On the other hand the following species have been recorded from most of the localities visited and hence considered common in the study area, such as Amaranthus viridis L. (Amaranthaceae), Calotropis procera (L.) R. Br. (Asclepiadaceae), Centella asiatica (L.) Urban (Apiaceae), Chenopodium album L. (Chenopodiaceae), Cleome rutidosperma DC. (Capparaceae), Eclipta alba (L.) Hassk. (Asteraceae), Nelsonia canescens (Lamk.) Spreng. (Acanthaceae), Ricinus communis L. (Euphorbiaceae), Shorea robusta Roxb. ex Gaertn. f. (Dipterocarpaceae) and Synedrella nodiflora (L.) Gaertn. (Asteraceae). 11. Ethnobotanical information collected from local people, specially from people belonging to Koch, Garo and Santal communities, are also provided. 12. The study has identified threats to the plant diversity of the district and has proposed some measures for their conservation.
Evaluation of antifungal activities of extracts of some medicinal plants on Neurospora Crassa
(University of Dhaka, 2016-01-10) Sultana, Razia
Antifungal activity was investigated using the leaf extracts of five different medicinal plants namely, Ocimum sanctum Linn., Coccinia cordifolia (Linn.) Cogn, Andrographis paniculata (Burm. f.) Wall., Centella asiatica (Linn.) Urban., Azadirachta indica A. Juss. against two fungi Neurospora crassa and Helminthosporium oryzae. The in vitro study revealed the presence of antifungal activity against Neurospora crassa in the leaf extracts of all the plants used during the study. The non sterilized leaf extracts was more effective than sterilized leaf extracts. The antifungal effect of these plant extracts enhanced gradually with the application of increased concentration and best antifungal activity was observed in the leaf extracts of Azadirachta indica A. Juss. as compared to all the tested plants. It inhibited the radial growth of both Neurospora crassa and Helminthosporium oryzae at 25% concentration. Antifungal activity was observed in the proteins present in the proteins of third fraction after (NH4)2SO4 gradient centrifugation and 200 µg of the total proteins of this fraction was found effective in controlling the fungal growth in vitro. Two proteins of the third fraction e.g., 40 and 37 kDa were found to be effective to control the fungal radial growth of both the Neurospora crassa and Helminthosporium oryzae.
Comparative eco- physiology of two cultivars of wheat (triticum aestivum cv. bari 26 and cv. pradip) in relation to soil moisture and salinity
(University of Dhaka, 2016-01-13) Hafiz, Shamima
Experiment has been done with two cultivars of wheat cv Bari 24 and Bari 26 in relation to salinity and soil moisture to study the growth, yield and water relations. Salinity experiment was done in the laboratory in Petri dishes. Two cultivars of wheat, Triticum asetivum (cv. Bari-24 (Pradip) and cv. Bari- 26) were grown in the different concentrations of sodium chloride solution and the seedling growth was observed. Shoot and root length of the seedlings of both cultivars of wheat showed a significant (P= 0.05) decrease at the highest salinity treatment but at the lowest salinity treatment i.e. at 0.05 M NaCl both shoot and root length increased. It is suggested that the growth of both cultivars of wheat seedling is favoured by low NaCl salinity. Seeds of two cultivars of Triticum aestivum (cv. Bari- 24 and cv. Bari- 26) were grown in the field under wet (watering everyday) and dry (watered once in a week) treatments. Six harvests were done with an interval of 7 days. Growth analysis from successive harvest of plants showed that early pattern of growth was influenced by moderate restriction in the availability of soil water and was associated with marked shift in the allocation of growth resources in favour of root development. Plant height, total dry weight, shoot and root dry weight, relative growth rate, and root: shoot ratio were analyzed after every harvest. In wet treatment, the number of lateral roots showed luxurious growth from those of dry treatment. Root and shoot length of both cultivars was significantly (P= 0.05) higher than dry treatment. Apart from total dry weight, the root and shoot dry weights were also higher in wet treatment than that of dry treatment. Relative growth rate (RGR) did not show significant difference between wet and dry treatments. Root/ Shoot ratio of both cultivars in all treatments from 3rd harvest onward showed an increasing tendency. Spike length and weight were maximum in cv. Bari 24 under wet condition and minimum was in cv. Bari 26. The maximum value of Flag leaf area was found in cv. Bari-26 in wet treatment and lowest was in cv. Bari 24 in dry condition. The area of flag leaf did not show any significant difference (P= 0.05) between the treatments but an increasing tendency of flag leaf area was noted under wet condition. Tissue water relations in wet and dry treatments were examined in leaf material collected from the field, with a view to obtaining comparative data on the mechanism of adaptation to drought. The relative water content was significantly (P=0.05) lower in cv. Bari 24 under wet condition than dry treatment and was highest in cv. Bari 26 in dry treatment plants. Wet treatment plants showed the maximum rate of loss of water, while dry treatment plants showed the lowest. The plants of these two cultivars of wheat showed a significant difference in their growth and yield in relation to soil moisture.
Aeromycoflora of Dhaka city, Bangladesh
(University of Dhaka, 2016-01-17) Sultana, Tania
The air influences every aspect of life and the activities of organisms affect the air. Sources of air borne microorganisms are everywhere. They are in food, water, on utensils and on bed sheets. The indoor and outdoor air is an important source of aeroallergens and pathogens. During the present investigation, monthly sampling of air borne mycoflora of Dhaka Metropolitan City, during February 2013 to January 2014 was recorded. The fungal colonies developed in PDA media were isolated from five different locations in the morning and evening in monthly intervals. The total number of counted fungal colonies were 6648 out of which in the morning was 3268 and in the evening it was 3380 and 156 colonies were sterile mycelia. The sampling sites were Sher-e Bangla Agricultural University, Gulistan, Dhaka Medical College, Sadarghat and DOHS, Mohakhali. The qualitative nature of the mycoflora, their mean, standard deviation, percent frequency and correlations to the total mycoflora, monthly periodicity have been described in this investigation. In this study, fifteen genera have been recorded viz. Alternaria, Arthrinium, Aspergillus, Bipolaris, Chaetomium, Cladosporium, Colletotrichum, Curvularia, Fusarium, Nigrospora, Penicillium, Pestalotia, Rhizopus, Syncephalastrum and Trichoderma under the class Ascomycetes, Zygomycetes and Deuteromycetes. Local fluctuations of the air borne fungi in relation to some meteorological parameters were also studied. The three most dominant fungal species were Aspergillus, Cladosporium and Penicillium contributing 30.71, 18.10 and 12.79% in the evening and in the morning it was 28.82, 15.78 and 11.53% in twelve months counting of the total colonies, respectively. Aspergillus was found in the highest frequency in the present investigation among the identified genera. In the present study Cladosporium was found 2nd position in term of its percent frequency. Maximum number of fungal colonies were found in Gulistan and Sadarghat in the morning and evening. During the twelve months investigation maximum fungal colonies were found in August and September as all the climatic factors were favorable for the fungal growth, their dispersal and survival. Among the fungi, found in the present investigation Alternaria, Aspergillus, Chaetomium, Cladosporium, Curvularia, Fusarium, Penicillium and Rhizopus were reported as pathogenic to plants and/or human and strongly allergenic to human. Bipolaris, Colletotrichum, and Pestalotia were reported as only plant pathogens. The present study contributes to our knowledge of air borne spores in the Dhaka City. Regular monitoring of air borne fungi can be helpful in the prevention of fungal allergic diseases in the city.
Development of disease resistant lentil (Lens culinaris Medik.) lines through Agrobacterium-mediated genetic transformation
(University of Dhaka, 2016-05-30) Das, Subroto Kumar
Agrobacterium-mediated genetic transformation was carried out to integrate fungal diseases resistant gene in microsperma varieties of lentil (Lens culinaris Medik.) cultivated in Bangladesh. As an integral part of Agrobacterium-mediated genetic transformation in vitro regeneration studies were carried out using various explants from Barimasur (BM) varieties, namely, BM - 1, BM - 4, BM - 5 and BM - 6. Among these explants cotyledon attached decapitated embryo (CADE) from BM - 6 appeared to be the best responsive explant towards in vitro regeneration compatible to Agrobacterium-mediated genetic transformation. Highest percentage (96%) of multiple shoots as well as healthy roots were obtained through direct organogenesis from CADE explant on MSB5 medium supplemented with 1.0 mg/l zeatin and 0.1 mg/l NAA. More than 90% of such developing explants produced effective, elongated and healthy roots when they were transferred to MS medium without any hormonal supplement. On the other hand, in vitro regenerated shoots those failed to develop roots were exploited to induce in vitro flower as well as seed to overcome the constraints created in producing in vitro roots in lentil to obtain complete plantlets. MS and half-strength of MS medium supplemented with various concentrations and combinations of IAA, IBA and NAA were employed for this purpose. The best responses regarding the development of in vitro flowers and pods were observed on half-strength of MS medium containing 20 mg/l IBA and 0.5 mg/l NAA. Healthy seeds obtained from this pods produced seedlings which were successfully transplanted to soil for further growth and development. Transformation experiments were performed using three strains of Agrobacterium tumefaciens, namely, LBA4404 harboring binary plasmid pBI121 containing GUS and nptII gene (Strain I), EHA105 harboring plasmid pGIIMH (strain II) containing bar gene resistant to phosphinothricin and also chitinase gene (as an antifungal gene) and the third one was LBA4404 containing binary plasmid pCAMBIA2300 (strain III) conferring nptII gene resistant to kanamycin and AFP gene as an antifungal protein gene. Strain I was mainly used for the optimization of transformation protocol and to select the suitable lentil variety as well as explant for transformation. Transformed shoots were selected using 2.0 mg/l phosphinothricin (Strain II) whereas 200 mg/l kanamycin was used to select transformed shoots in case of strain I and III. Transformation efficiencies for strain I, strain II and strain III was 2.15, 0.36 and 0.47% respectively. Stable integration of desired gene within the lentil genome was confirmed through PCR, RT-PCR, Southern and Northern hybridization techniques. Seedlings developed through transformation were successfully transferred to soil for the development of transformed progenies in lentil.
Taxonomic studies in the family araceae from Bangladesh
(University of Dhaka, 2016-08-21) Ara, Hosne
1. The family Araceae has been investigated throughout the country by extensive field trips (137 field trips) during the period from 1988 to 2014. Collection, preservation and identification of specimens have been made following standard taxonomic procedures. 2. Taxonomically important 60 plant specimens, which were not readily identifiable, were collected and planted in the Bangladesh National Herbarium Garden, Dhaka University Botanical Garden and Home Garden for critical study. 3. A total of 27 genera, 105 species and 6 varieties have been recorded from Bangladesh territory. 4. The study has identified 4 new generic (Ariopsis Nimmo, Caladium Vent., Gonatopus J.D. Hook. ex Engl. and Remusatia Schott) and 38 new species records for Bangladesh. 5. Six new species and four new varieties have been ascertained.
Seasonal variation and interrelationship of phytoplankton and Vibrio Cholerae in Bangladesh
(University of Dhaka, 2016-08-22) Islam, Nasima
A total of 17 water variables were studied of the two distinct different geographical areas in Bangladesh for two years (October 2010-September 2012). Out of the two study sites, Mathbaria represents estuarine cholera epidemic pattern whereas Chhatak represents inland epidemic pattern for Vibrio cholerae. In Mathbaria there are four infested stations among eight stations and in Chhatak site there are two infested stations among seven stations. After analyzing the studied variables, it is observed that in Mathbaria site Vibrio cholerae showed a single peak during summer in the month of March through May. Whereas in Chhatak sites cholera peak showed a single peak during autumn in the month of early November i.e. just after the monsoon which contain warm, humid temperature. Stations of Mathbaria showed high level of total dissolved solids (TDS) and salinity while the stations of Chhatak showed higher range in the concentration of soluble reactive phosphorus (SRP), soluble reactive silicate (SRS), nitrate nitrogen (NN), chlorophyll a, phaeopigment (PP), phytoplankton and zooplankton densities. Higher ranges of SRP and NO 3 -N were found in the infested stations of both the study sites. Maximum cell density of Vibrio cholerae at Mathbaria was nearly 500-fold more than Chhatak site. Dominant Phytoplankton in the infested stations of both the study sites belonged to euglenoid and diatoms. During cholera peak of Mathbaria, peak of water temperature, alkalinity, salinity, pH, total dissolved solids (TDS) and phaeopigment also showed the same peak during summer. On the other hand, infested stations of Chhatak showed peak of soluble reactive phosphorus (SRP), nitrate nitrogen (NN) and phaeopigment during autumn season when Vibrio cholerae also showed peak. Pearsons correlation (SPSS v11.5) analysis among the studied variables reveals a significant negative correlation between phytoplankton density and water temperature. In this analysis on one hand significant positive correlation was observed between the phytoplankton and total zooplankton densities. On the other hand, a significant positive correlation between the concentration of phaeopigment and V. cholerae in Mathbaria Station 2, 7 and 10 and in the Station 2 of Chhatak was observed. Phaeopigment (phaeophytin a, cholorophyllide a and two unidentified pigments) is a degraded product of chl a, dominant pigment of phytoplankton. In the analysis, significant positive correlation was also observed between phytoplankton density and total zooplankton. Grazing by copepod (zooplankton) is the major reason for the degradation of chlorophyll a to phaeopigment. So, it can be said that, phytoplankton enhances the growth of zooplankton since peak growth of both phyto- and zooplankton is nearly overlapping or occurs side by side. After the peaks achieved, the plankton population start declining during which a lot of phaeopigment is released in the habitat. Under this enriched conditions of phaeopigment in the habitat, peaks of V. cholerae are mostly observed. To support the strong relationships among the studied environmental and biological variables and sampling periods RDA (Canoco v4.54) is also applied. Results by this multivariate program also support the similar relationship.
Development of in vitro plant regeneration system and agrobacterium–mediated genetic transformation in Mungbean (Vigna radiata (L.) wilczeck)
(University of Dhaka, 2017-11-01) Begum, Setara
An efficient protocol has been developed for Agrobacterium-mediated genetic transformation of two important mungbean (Vigna radiata (L.) Wilczeck) varieties cultivated in Bangladesh, namely, Binamoog-5 and BARI mung-6. Prior to transformation an efficient in vitro regeneration protocol was developed for these two mungbean varieties. Cotyledonary node, shoot tip and cotyledone attached decapitated embryo were used as explants for direct regeneration of shoot. MS medium with various combinations and concentrations of BAP, Kn and NAA were used for direct regeneration of shoots. MS medium supplemented with 10.0 μM BAP and 0.5 μM NAA was found to be the best towards the development of highest number of multiple shoots. Full strength of MS medium supplemented with 2.0 μM IBA was found to be the most effective for healthy root induction from the regenerated excised shoots. Following root induction the in vitro regenerated plantlets were successfully transplanted to soil. Transformation experiments with cotyledone attached decapitated embryo, cotyledonary node and decapitated embryo explants were conducted using Agrobacterium tumefaciens strain, namely, LBA4404 harboring the binary plasmid pBI121 conferring GUS (β-glucuronidase) and nptII (neomycin phosphotransferase II) genes. Transformation experiments were monitored through GUS histochemical assay since the strain of Agrobacterium contained GUS gene. Different factors influencing successful transformation such as, density of bacterial suspension, incubation and co-cultivation periods were optimized. Maximum responses towards transformation were obtained with bacterial suspension having an optical density of 0.56 at 600 nm. Moreover, 30 minutes of incubation period followed by 72 hours of co-cultivation period were found to be the most effective towards transformation as determined by transient GUS assay. Selection of transformed shoots was carried out using different concentrations of kanamycin as the Agrobacterium strain contained nptII gene. Transformed shoots were selected using 150 mg/l kanamycin. The survival of green shoots on the optimum selection medium indicated the production of transformed shoots. Stable expression of the GUS gene was detected in various parts of transformed plantlets. Putatively transformed shoots were rooted on full strength of MS medium containing 2.0 μM IBA and 100 mg/l ticrecilin. Rooted transformed plantlets were successfully transferred to soil. Genomic DNA was isolated from the putatively transformed mungbean shoots and stable integration of GUS and nptII genes was confirmed by polymerase chain reaction (PCR) analysis.
In vitro regeneration and development of stress tolerant peanut (arachis hypogaea l.) through agrobacterium-mediated genetic transformation
(University of Dhaka, 2018-12-23) Banu, Tanjina Akhtar
Peanut (Arachis hypogaea L.) is one of the most economically important oilseed crop of the world. Bangladesh has a great opportunity to cultivate peanut in the marginal lands where hardly any other economically important crops are growing. However, in Bangladesh peanut production is hampered due to the incidence of various fungal diseases. The modern techniques of biotechnology such as plant genetic transformation can be applied for its improvement towards the development of disease resistance. The objective of the present investigation was to develop a fungal disease resistant peanut line through Agrobacterium-mediated genetic transformation. As a prerequisite of the transformation protocol, an efficient in vitro regeneration system was established for three locally grown peanut varieties, namely, Dhaka-1, BARI Chinabadam-8 and Binachinabadam4. Four different types of explants, namely, immature leaflet, decapitated half embryo, deembryonated cotyledon and single cotyledon attached decapitated embryo were used for regeneration. Highest percentage (71.8%) of multiple shoot regeneration was achieved when de-embryonated cotyledon explants initially cultured on 88.8 µM BAP, followed by two subsequent cultures on lower concentrations of BAP (66.6 µM BAP and 13 µM BAP) containing medium. It took about 45 days for the regeneration of multiple shoots. Best response towards induction of roots for all the varieties was obtained when regenerated shoots were cultured on half strength of MS medium supplemented with either 2.5 µM IBA or 1.0 µM IAA. Fully developed in vitro regenerated plantlets were successfully established in soil for further growth and development. For optimization of genetic transformation protocol, Agrobacterium strain LBA4404 containing binary vector plasmid pBI121GUS-NPTII harboring GUS (β-Glucoronidase) and nptII (neomycin phosphotransferase) genes (construct I) was used. Transient GUS histochemical assay revealed that among the three explants used maximum transient GUS expression (86.66%) was observed from de-embryonated cotyledon explants of variety Dhaka-1 having an optical density of 0.8 at 600 nm with 10 minutes incubation period. Transformed shoots were cultured on 200 - 250 mg/l kanamycin supplemented medium to select the putatively transformed shoots. Transformation frequency was found to be 0.34% in Dhaka-1 using pBI121GUS-NPTII construct. Agrobacterium strain LBA4404 containing plasmid pCAMBIA2300enh35SAFP harboring AFP (antifungal protein) gene and nptII (neomycin phosphotransferase) (construct II) was used for the integration of gene of interest. De-embryonated cotyledon and single cotyledon attached decapitated embryo explants of variety Dhaka-1and BARI Chinabadam-8 were used for transformation experiments. Among the two explants best response was observed from de-embryonated cotyledon explants. In this case, transformation efficiency was found to be 1.52% in Dhaka-1 and 0.85% in BARI Chinabadam-8. A total 17 putatively transgenic plants (T ) of Dhaka-1 were confirmed through PCR analysis. The integration of nptII gene was further confirmed by Southern blot hybridization in 10 T 0 peanut plants survived through acclimatization and developed till maturation. T 1 0 seeds were collected and raised following the Biosafety guidelines in the double layered insect proof net house for further investigation. Peanut as a grain legume has been considered as recalcitrant towards in vitro plant regeneration as well as for genetic transformation. The results of both in vitro plant regeneration and Agrobacterium-mediated genetic transformation using marker as well as antifungal (gene of interest) gene has pave the way for developing fungal disease resistant peanut plants.
Effects of aluminium toxicity on ion transport in Oryza sativa l. and Cicer arietinum l. in relation to biochemical and anatomical changes
(University of Dhaka, 2018-12-26) Samad, Rifat
Aluminium, at concentrations of 10, 50, 100 and 150 µM, inhibited germination of rice and chickpea seeds. Aluminium stress decreased accumulation of K in the radicle and plumule of germinated rice and chickpea seeds. On the other hand, Cl - accumulation was increased by a maximum of 2- to 2.4-fold in the radicle and plumule of germinated rice and chickpea seeds following Al treatment. Similarly, Al (10-150 µM) caused a few fold increase in accumulation of Al 3+ in the radicle and plumule of germinated rice and chickpea seeds. Aluminium-induced decrease in K + content with concomitant increase in Cl and Al 3+ content in the radicle and plumule might be correlated with the inhibition of germination. Aluminium decreased K + accumulation in the root and shoot of rice, and the root, stem and leaves of chickpea seedlings grown in solution culture. On the contrary, different concentrations of aluminium caused a few fold increase in Na + in rice and chickpea. Aluminium stress caused a dramatic increase in Cl - accumulation in different parts of rice and chickpea seedlings. But aluminium toxicity decreased NO accumulation in rice and chickpea. Al stress decreased phosphate accumulation in rice and chickpea seedlings. Aluminium toxicity inhibited the accumulation of Ca 2+ , Mg 2+ and Fe in the root and shoot of rice, and the root, stem and leaves of chickpea plants grown in both solution and sand culture. in different parts of rice and chickpea seedlings grown in solution culture. Application of aluminium caused a dramatic increase in accumulation of Al Exposure of rice and chickpea seedlings to different concentrations of aluminium led to a stimulation of reducing and total sugar in the root, stem and leaves. Similarly, Al stress increased proline and total amino acid contents in different parts of rice and chickpea seedlings. Aluminium toxicity caused a dramatic increase in peroxidase and catalase activity in the root and shoot of rice. 150 µM Al caused a 8- to 9-fold increase in peroxidase and catalase activity, respectively, in the root of rice. On the contrary, Al stress decreased superoxide dismutase (SOD) activity in the root and shoot of rice. In chickpea, Al stress caused a few fold increase in peroxidase, catalase and SOD activity in the root and leaves. A dramatic 14.8- and 14.6-fold increase in SOD activity was recorded in the root and leaves of chickpea seedlings respectively. It is interesting to note that there is a generic difference between rice and chickpea with respect to the effect of aluminium stress on SOD activity. Aluminium toxicity caused a dramatic increase in phenolic compounds in rice and chickpea plants grown in sand culture. Aluminium stress resulted in a reduction of chlorophyll a, chlorophyll b and carotenoid contents in the leaves of rice and chickpea plants. Exposure to aluminium decreased primary root length and number of lateral roots in rice and chickpea seedlings grown in rhizobox. Aluminium toxicity inhibited the root and shoot length of rice and chickpea seedlings grown in solution culture. Aluminium stress decreased the dry weight of root and shoot of rice and chickpea seedlings. But it increased shoot/root dry weight ratio. Aluminium toxicity reduced the number of metaxylem vessels in the root of rice. Number of sclerenchyma cells were more in aluminium-treated rice root. Smaller sized vascular bundles were found in the leaf of rice under Al stress. In chickpea, Al decreased the size and number of vessels in the root. Number of palisade parenchyma was reduced in the leaf of chickpea. Al treatment caused closure of stomata both in rice and chickpea leaves. The effect of aluminium toxicity on ion transport and its correlation with biochemical changes and anatomical structure, and growth is discussed.
Genetic diversity analysis and development of in Vitro regeneration system in selected clones of tea (Camellia sinensis l.) plant
(University of Dhaka, 2019-01-14) Boonerjee, Shefali
The present study was carried out with an aim to analyze the genetic diversity of eighteen tea (Camellia sinensis L.) clones as well as to develop an in vitro regeneration system for selected tea clones of Bangladesh. Genetic diversity among the 18 tea clones was analyzed using Random Amplification of Polymorphic DNA (RAPD) markers. Twenty arbitrary oligonucleotide primers were used for this purpose. All the investigated primers exhibited significant amplification following PCR analysis. The primers amplified reproducible and scorable bands all across the investigated tea clones. A total of 755 bands were produced in all the 18 tea clones with an average of 37.75 RAPD bands per primer. Among all the bands 97.41% were polymorphic in nature. The molecular size of the amplified DNA fragments ranged from 250 to 5000 bp. The highest number of amplified products was recorded in case of the primer OPA-7 (95 bands). Whereas primer CO2, OPA-1 and OPA-2 produced 71, 58 and 52 bands respectively. The lowest number of bands was found in case of primer B06 (14 bands). Ten unique clone specific bands were obtained from the genome of the 18 tea clones. The values of pairwise genetic distance among the clones ranged from 24.0 to 59.0, indicating the presence of wide range of genetic diversity. The highest genetic distance (59.0) was found between the clone BT13 and BT1, whereas that of the lowest (24.0) was obtained between the clone BT18 and BT5. Dendrogram based on Nei’s genetic distance was constructed using Unweighted Pair Group of Arithmetic Mean (UPGMA) where the 18 tea clones were grouped into two major clusters: BT9 and BT13 in cluster 1 and the remainder of 16 clones in cluster 2. The cluster 2 is further sub-divided into many sub-clusters. Cluster analysis revealed that the clone BT5 is closely related to BT18. An in vitro regeneration system for the clones of tea plant was also developed through direct and indirect organogenesis using shoot tip, nodal segment and cotyledon explants. MS medium supplemented with 2.0 mg/l BAP and 0.1 mg/l IBA was found to be effective for the initiation and multiplication of shoots directly from the shoot tip and nodal segment explants. Elongation of such multiple shoots was effected by the addition of 0.5 mg/l GA3 in the shoot multiplication medium. For indirect organogenesis, the highest amount of callus was obtained using MS medium containing 4.0 mg/l 2, 4-D from de-embryonated mature and immature cotyledon explants. Moreover, morphological differentiation of these calli was achieved when these explants were cultured on the MS medium supplemented with 2.5 mg/l BAP and 0.1 mg/l Kn. The highest root induction was achieved when micro shoots were treated with 500 mg/l of IBA for 30 min before transferring them to the soil. After proper hardening rooted plantlets were established in the soil. Genetic variability was assessed among the micropropagated plants derived from the in vitro culture of BT2 clone using eleven RAPD primers. A total of 601 bands ranging from 300 bp to 2900 bp were produced within the examined 17 micropropagated and 1 field grown plants. Among the 11 primers, 7 produced 504 monomorphic bands for all the plants. However, remaining 97 bands were polymorphic in nature and maximum were amplified for three (S4, S14 and S15) micro-propagated plants. The dendrogram tree showed 18 plants were closely grouped into 2 main clusters where the mother plant BT2 (S18) had separately made a position with the cluster 1. The micropropagated plant S14 and S4 each separately had created their position under 2 nd main cluster whereas the remaining plants were arranged under sub cluster1. Moreover, a lower level of genetic distance (0-14) was revealed among the micropropagated plants from the genetic distance matrix.
Taxonomy and reproductive biology of the family liliaceae of Bangladesh
(University of Dhaka, 2019-01-23) Afroz, Sumona
The family Liliaceae A.L. de Jussieu has been revised for Bangladesh and a total of 43 species under 20 genera have been recorded. A complete taxonomic account of the family is therefore prepared for the flora. The taxonomic history and currently accepted classification of the family Liliaceae is presented and discussed. Artificial dichotomous bracketed keys to the genera and species (wherever necessary) have been provided for easy identification of the taxa. Updated nomenclature i.e. valid names, synonyms, local names and English names where available, and descriptions have been furnished under each taxon including photographs. Flowering and fruiting periods and distribution have also been added. The germplasm of most of the taxa have been collected from different parts of the country and planted in the experimental plots of the Dhaka University Botanical Garden. Out of 43 species, 21 species are wild and 22 are cultivated. Among the wild species Asparagus racemosus Willd., A. densiflorus (Kunth) J.P. Jessop and A. setaceous (Kunth) J.P. Jessop are climbers. Hypoxis aurea Lour., Asparagus setaceous (Kunth) J.P. Jessop, Asphodelus tenuifolius Cavan and Crinum stenophyllum Baker were previously recorded but we did not find any live specimens in the wild. Some species are restricted to certain area like Urginea indica (Roxb.) Kunth in Cox's Bazar district near Himchari and Allium tuberosum Rottler ex Spreng. in Belaichari of Rangamati district. Chlorophytum nepalense (Lindley) Baker was collected from Runctia Sal forest under Sherpur district in 2008 and planted in the Dhaka University Botanical Garden. This species has been recorded as new for the flora of Bangladesh. Despite repeated field trips were made in that area for further collection, no specimen of Chlorophytum nepalense were found and therefore this species could be claimed as very rare or possibly extinct in Bangladesh. Hymenocallis littoralis (Jacq.) Salisb., an ornamental herb collected from Sonargaon and Char Kukri Mukri was not recorded previously, hence it is a new record for Bangladesh. Some other species, viz. Allium chinense G. Don, Asparagus densiflorus (Kunth) J.P. Jessop, A. officinalis L., Chlorophytum comosum R.Br., Crinum amabile Donn, C. jagus (Thomps.) Dandy, Eucharis grandiflora Planch. & Linden, Eucrosia bicolor Ker-Gawl., Hippeastrum puniceum (Lamk.) Voss, Proiphys amboinensis (L.) Herb., Zephyranthes atamasco (Linn.) Herb. are usually cultivated in the gardens, were not recorded in any literature published previously for this region. Reproductive Biological data of important 14 species under 11 genera are presented and discussed. Among these species Allium tuberosum Rottler ex Spreng., Asparagus racemosus Willd., Chlorophytum nepalense (Lindley) Baker and Urginea indica (Roxb.) Kunth are cross pollinated. Pollination occurred by ant or bee belonging to the family Formicidae or Apidae. Most of the species are self pollinated. Hemerocallis fulva L. produced no fruit and Pancratium triflorum Roxb. produced fruit but not matured. Asparagus racemosus Willd. and Haemanthus multiflorus Martyn ex Willd. produced very poor number fruits in comparison to the number of flowers bloomed. Out of studied 14 species of Liliaceae, 10 species were propagated through seeds. Seeds were not germinated in Curculigo orchioides Gaertn. and Scadoxus multiflorus Raf. Two species e.g. Hemerocallis fulva L. and Pancratium triflorum Roxb. produced no fruit. Minimum time taken for seed germination is 3-4 days in Zephyranthes spp., whereas maximum 1 year in Crinum amoenum Roxb. Propagation through bulb or rhizome transfer was not possible in Asparagus racemosus Willd., Chlorophytum nepalense (Lindley) Baker and Zephyranthes tubispatha (L'Her.) Herb. whereas rest 11 species propagated through bulb or rhizome. Minimum time taken for scape initiation to fruit maturation were 16 days in Zephyranthes spp. and maximum about 80 days in Gloriosa superba L. from initiation of aerial stem. Maximum about 100 flowers borne on a scape in Scadoxus multiflorus Raf., whereas single flower in Gloriosa superba L. and Zephyranthes spp. Asparagus racemosus Willd. and Haemanthus multiflorus Martyn ex Willd. produced single seed, while Gloriosa superba L. contains about 50-75 seeds in each fruit. Production of fruits and seeds were very poor compare to number of flowers in Allium tuberosum Rottler ex Spreng., Asparagus racemosus Willd. and Scadoxus multiflorus Raf.
Taxonomy, propagation and chemical properties of selected Anticancerous plants of Bangladesh
(University of Dhaka, 2019-06-20) Sultana, Nahid
This dissertation explains the identification of the anticancerous plants of Bangladesh and their taxonomic enumeration, propagation experiment of some selected anticancerous plants and chemical and biological investigation of two anticancerous plants of Bangladesh, namely Aphanamixis polystachya (Wall.) R. N. Parker and Oroxylum indicum (L.) Kurz. Oroxylum indicum belongs to the family Bignoniaceae is a deciduous tree, characterized by compound leaf, long terminal raceme, zygomorphic flowers, campanulate calyx, 5 stamens, axile placentation, sword-like fruits, winged seeds. Aphanamixis polystachya belongs to the family Meliaceae is an evergreen tree characterized by compound leaf, sweet-scented flowers, reddish calyx, waxy petals, 6 stamens, 3-lobed stigmas, obovoid fruits and plano-convex seeds. Over 3000 plant species have been used in one way or another for cancer treatment. In Bangladesh, a total of 220 plant species have been identified having anticancerous properties through literature survey. Propagation experiment of 10 species were carried out. Among them, the highest germination rate (100%) was observed in Plumbago zeylanica and the lowest germination rate (10%) was noticed in Abrus precatorius. In case of Vitex trifolia, seeds were not germinated, however, this plant species was propagated by stem cutting process. Out of the five stem cuttings, all five came out to leafy branches in Vitex trifolia. A thorough and systematic study has been carried out in order to isolate compounds having anticancer properties. The study describes the isolation and characterization of compounds from the root bark of O. indicum, and bark and leaves of A. polystachya. In addition, the crude methanol extract of the root bark of O. indicum, and bark and leaves of A. polystachya and its different soluble partitionates i.e. petroleum ether, DCM (dichloromethane), chloroform, ethyl acetate and aqueous soluble fractions were obtained by Kupchan partitioning subjected to screenings for anticancer activities.
Molecular Cytogenetics of Crotalaria Spp. From Bangladesh.
(University of Dhaka, 2019-10-03) Warasy, Ashma Ahmed
Ten germplasm of Crotalaria species viz. C. pallida (Acc. No. 4250, 4803, 4805, 4806 and 4807), C. incana (Acc. No. 4790, 4801, 4804 and 4809) and C. juncea (Local) available in Bangladesh were investigated cytogenetically and at the molecular level using RAPD- and SSR- markers for their authentic characterization. The interphase nuclei and prophase chromosomes of these germplasm exhibited different types of orcein-staining patterns. Persistent nucleolus was observed in Acc. No. 4806 of C. pallida following orcein staining. Variable numbers of somatic chromosome numbers were found in Crotalaria species. In C. pallida 2n = 16 (Acc. No. 4803, 4805 and 4807) and 2n = 18 (Acc. No. 4250 and 4806) chromosomes were observed. In contrast, C. incana was found to possess 2n = 16 (Acc. No. 4801), 2n = 17 (Acc. No. 4790 and 4804) and 2n = 18 (Acc. No. 4809) chromosomes while 2n = 16 somatic chromosome number was observed in C. juncea. Somatic chromosome number found of 2n = 17 in Acc. No. 4790 and 4804 of C. incana might be originated either by intra-specific hybridization between 2n = 18 and 2n = 16 germplasm or by aneuploid origin that correlates with their phenotypic features like seedless pod formation. Thus it is suggested to avoid these two germplasm for further breeding programme. In ten germplasm of Crotalaria the variation of chromosomal length was almost negligible. Metacentric chromosomes were found in maximum germplasm indicate their symmetric nature of karyotype. In contrast, few submetacentric chromosomes were observed in several germplasm indicate relatively asymmetric nature of their karyotype. After CMA-banding, ten Crotalaria germplasm generated 31 centromeric and 34 terminal bands which indicated a tendency of accumulating GC-rich sequences at centromeric regions or chromosomal ends. The number of DAPI-bands was less than that of the CMA-band found in different germplasm of Crotalaria. Maximum terminal DAPI bands indicated a tendency of accumulating AT-rich repetitive sequences at the chromosomal ends. Few chromosomes could be used as marker of respective germplasm due to their unique DAPI-banding pattern. Fluorescent banding revealed the occurrence of genomic alteration within these germplasm. Further genomic DNA from the ten Crotalaria germplasm was studied using fourteen oligonucleotide primers and four microsatellite primer pairs for RAPD and SSR analysis, respectively. The fourteen RAPD primers generated 881 distinct bands with 95.57% polymorphisms indicating highly diverged nature of germplasm. In addition to polymorphism, 86 unique and 50 common RAPD bands were identified in ten Crotalaria germplasm. The four SSR primer pairs generated 107 distinct bands of which all were considered as polymorphic. Moreover, 19 unique SSR bands were identified among them. The dendrogram of RAPD and SSR showed that the Acc. No. 4803 of C. pallida and Acc. No. 4790 of C. incana were distinctly different from the rest and placed alone in a separate cluster that correlated with its phenotypic and cytogenetical features. Therefore, each germplasm of Crotalaria could be characterized authentically by cytogenetical and molecular analysis.